Free SMTP Server Setup with Postal (Step by Step Guide)

Postal Free SMTP server

In this Step by Step Guide, I will show you how to set up a Free SMTP server using Postal, the open source SMTP software, and connect it to your email marketing applicaiton to send Unlimited Emails*.

Also, you will find a video below Showing the setup if you feel something is unclear.

There are several methods to build SMTP servers, in this guide I will build the SMTP server using a free open source software called “Postal“.

Postal is a fully-featured open source mail delivery platform for incoming & outgoing e-mail and gives you all the tools and features needed to build a full mailing system for your business.

What is the SMTP Server?

I don't like robotic definitions like Wikipedia, I love to make things simple. So…

Simply, SMTP is that thing that allows you to send emails over the internet.

SMTP stands for “Simple Mail Transfer Protocol”. It's a Concept in Networking that you don't have to worry about.

Just Know that SMTP is the technical thing that is responsible for delivering emails over the internet.

Let's connect things, how this is related to email marketing?

I think it's clear, but just in case, and As I explained in my Techincal Email Marketing guide, any Email marketing system consists of two parts:

  • The sender: (SMTP service) this is the technical part. It allows you to send emails over the internet.
  • The Management Application, where you can configure and manage your Email Lists, Marketing Campaigns, monitor and analyze results, manage your sending servers, and so on.

So we connect both together to get an Email Marketing System.

postal free smtp server setup
Email Marketing System

So now I think It's SUPER clear, we are going to learn how to build the first part of any email marketing system which the SMTP server.

Need more details?

Maybe you are that person who loves to go deep in topics and understand everything in detail like me ???? if you are that person, you can watch the following 3 minutes video to learn more about SMTP servers and how it works:

You can find more videos on my YouTube Channel.

What do we mean by Sending Unlimited Emails?

When we say unlimited emails, this means that we can send unlimited emails from our server, there are no restrictions by companies or monthly plans to buy or so.

It's your own server, u can send as much your server can handle in terms of resources. so when you have more (CPU and RAM), you can send more emails and so on.

Setup the SMTP Server, Let's Start!

Ok, So Let's start the real work! but before, you need to know what is required.

Requirements to Setup SMTP Server.

In order to Build and Setup an SMTP Server, you will mainly need two things:

  1. A Domain name
  2. VPS Server with port 25 opened.

1. Domain name

When you send emails, you will be sending from an email address like this one:

[email protected]

So in my case, “” is the domain name that I use to send my emails. so simply it's required to have a domain name to use when you send emails from your SMTP server.

Usually, it's your website domain name, except if you are working with cold emails, then it's better to get and use another domain in case it got blacklisted, to keep your main business domain safe.

So if you don't have a domain yet, go and get one NOW! in order to continue the Setup.

How to get a domain? simply you buy one! and it costs around 10$ per year, so it's not that big deal!

We have a lot of DOMAIN REGISTRATION PROVIDERS where you can get a domain from like:

Here in the course, I will be using Godaddy to get my domain, but you can use any other service if you want, all work in the same way, and if you need any help,  I will be here 🙂

You can watch this 3 minutes video to see how to get and buy a domain from Godaddy Domain Registrar if you are a beginner.

This video is part of my Top Rated Course On Udemy:
Build Your Own SMTP and Send Unlimited Emails

Got a Domain? Great! ✔️ Let's continue.

2. VPS Server with Port 25 opened.

The second thing you will need is a VPS server. a public server to install & Setup SMTP on.

What is a VPS server?

If you don't know what is a VPS server, simply its a computer (a server) running in the cloud that you buy from a Web Hosting or Cloud Services company. And it's publicly accessible with a Public IP.

A VPS can be used to host your websites with higher performance, can be used to run a machine 24/7 in the cloud to do any task you want.

Note: If you are interested in learning how to host your own websites on a VPS server, you can

Anyway, In our case, we will be using the VPS Server for Building an SMTP server.

Port 25 open??

I mentioned that the VPS must have port 25 opened, what does this mean?

I don't want to bother your head within deal technical stuff but in short. Any network service or software uses a certain port to communicate over the internet or network. Examples:

  • Connecting remotely to another Windows Machine using RDP software works over port 3389.
  • SQL database systems like MYSQL on our computer works over port 3306.
  • Connecting to a Linux machine remotely to manage it with SSH, uses port 22.
  • When you surf the web and open websites, we use port 80. and so on.

By default, all servers and computers have a firewall running which blocks all ports except the ones you want. so In order to use a certain service, we need to open that port in the firewall.

What you have to know also, that ports can be blocked and opened in two ways, incoming and outgoing, the following diagram will make things clearer:

Setup SMTP Server - ports
Inbound and Outbound Ports

I recommend you to watch my free course “Amazon EC2 for Digital Marketers” you will understand all these concepts in less than an hour.

So, in our case, we are building an SMTP server, and the SMTP software or protocol communicates over port 25. so we need to have port 25 opened.

So when you get a VPS server, just make sure that the company allows Port 25 an don't block it, because some companies do this to protect from spammers.

Setup SMTP Server port 25
Port 25 is used to send emails

Here is a list of some companies that allows port 25 by default:

  1. Host wind.
  2. Contabo.
  3. Interserver.
  4. OVH.
  5. Digital Ocean*
  6. AWS (some accounts are blocked)

*Digital Ocean Sometimes block some accounts and restrict port 25, but in general they allow all ports.

Are there any other Companies?? yes, simply you can contact the support of any company you want and ask if they block any ports by default. if not, then perfect, you can go with it.

Feel free to use any VPS company you want, It's up to you!

You can also sign up on DigitalOcean through the coupon link below to get free 100$ to test everything free.

Or Start with Contabo which I think its the cheapest VPS service that you can use, I have 2 servers configured with Contabo.

After you select your VPS company, just create a VPS Server with the following specifications:

  • Ubuntu 18 x64 as your operating system
  • You can start with 1 CPU/2 GB RAM (And resize later).

Got your VPS? Great! ✔️ Let's continue.

VPS Server basic configuration.

Now we have our new Ubuntu VPS server, Let’s prepare it for out Setup.

Connect to your server, using an SSH client like putty or bitvise.

First, check your hostname:

hostname -f

If you don’t see a form of ANYTING.YOURDOMAIN.COM, then you need to change the hostname using the following command:

 sudo hostname host.domain.tld 

Where the host is anything you want. so in my case, my sample domain for this tutorial is, the command will look like this:

sudo hostname

Map your domain name.

Now we have our VPS server and we set its name. Go to your Domain Provider and map your Domain to your VPS server. simply open DNS management zone and add a new A record like this:

host: server points: YOUR SERVER IP.

Setup SMTP Server - Godaddy A record
Godaddy A record

*server is in my case, you can choose whatever you want for your server name.

Done? ✔️ Let's continue.

Setup Free SMTP Server

The VPS is ready, and we can start the installation process. So in order to setup SMTP Server on our VPS, we need to install an SMTP software.

Install Postal Free SMTP Software


Postal runs entirely using containers which means to run Postal you'll need some software to run these containers. We recommend using Docker for this purpose but you can use whatever software you wish.

To install docker, run below commands. (NOTE: Each command starts with a – )

-sudo apt-get update
-sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg \
-curl -fsSL | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
-echo \
  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
-sudo apt-get update
-sudo apt-get install docker-ce docker-ce-cli
-sudo curl -L "$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
-sudo chmod +x /usr/local/bin/docker-compose
-docker-compose --version

System utilties

There are a few system utilities that you need to have installed before you'll be able to run some of the Postal commands.

apt install git curl jq

Git & installation helper repository

Make sure you have git installed on the server by running below commands.

-git clone /opt/postal/install
-sudo ln -s /opt/postal/install/bin/postal /usr/bin/postal

Maria DB

You can run MariaDB in a container, assuming you have Docker, using this command. Copy and paste this all in Putty.

docker run -d \
   --name postal-mariadb \
   -p \
   --restart always \
   -e MARIADB_DATABASE=postal \

This will install your postal database on MariaDB.


RabbitMQ is responsible for dispatching messages between different processes. As with MariaDB, there are numerous ways for you to install this. For this guide, we're just going to run a single RabbitMQ worker. Copy all the below as one command and paste on putty.

docker run -d \
   --name postal-rabbitmq \
   -p \
   --restart always \


Run the command below and replace with the actual hostname you want to access your Postal web interface at. Make sure you have set up this domain with your DNS provider before continuing.

postal bootstrap postal.YOURDOMAIN.COM

Initializing the database

Run the following commands to create the schema and then create your first admin user.

postal initialize
postal make-user

Running postal

You're now ready to run Postal. You can do this by running:

postal start

This will run a number of containers on your machine. You can use postal status to see details of these components.

Installing WEB Client

You can use any web client to run postal on your web, but in this guide, we are going to use Caddy. Install it with an SSL using below command.

docker run -d \
   --name postal-caddy \
   --restart always \
   --network host \
   -v /opt/postal/config/Caddyfile:/etc/caddy/Caddyfile \
   -v /opt/postal/caddy-data:/data \

Once this has started, Caddy will issue an SSL certificate for your domain and you'll be able to immediately access the Postal web interface and login with the user you created in one of the previous steps.

Configure Postal SMTP

Now, Open your Internet browser, and navigate to your Server IP URL or Subdomain like this:


You will notics an SSL warning, It's ok just proceed as you see in the image below:

SSL warning
SSL warning

And then the Postal Login Screen will open, enter your email and password that you created during the setup to login.

Postal Login
Postal Login

And Now, you are inside Postal, click “Add Organization” to add one.

Then Click on Build Mail Server and enter the name, and set it to live mode

postal free smtp server setup
Create Postal Mail Server

So Simple. ✔️

Postal Domain Configuration

Now, Click On Domains to add you domain name into Postal

Add Domain in Postal
Add Domain in Postal

Enter your Domain name that you want to use to send emails, and Click Create Domain.

Then, Postal will show you the Domain page with the records that you need to configure.

Postal DNS records
Postal DNS records

So, What you need to do simply, is to copy these records and paste in your DNS Zone. and then your server will be ready to send emails! but what are SPF and DKIM?

Dkim (DomainKeys Identified Mail) :

Let's Start with DKIM, A DKIM record is also a text record in your DNS that holds a public authentication key. This key will be validated using a private key saved privately inside your server.

All emails will be signed, and this will avoid any alterations and protect your email originality, and this is very important for your server to archive high sending scores.

Watch this video for more info:

Setup Dkim For Postal

What's nice about Postal, is that DKIM is already configured and the keys are generated, you just need to copy the DKIM record to your DNS Zone.

Postal DKIM
Postal DKIM record

SPF (Sender Policy Framework):

An SPF record is a TXT record that is added to your Domain DNS Zone and allows you to set the mail servers that are allowed to send emails from your domain.

Messages sent from a server that isn’t included in the SPF record will be marked as spam or rejected.

As an example, you can’t send an email from your own server and set your sending email as “,” you can’t use google’s domain. It indicates that you are trying to spam.

In the same way, you can configure SPF and prevent anyone from using your domain to send emails,  So setting SPF is very important when it comes to making your domain trusted by other mailing providers.

To set up SPF. Open your DNS zone in and add the following record:

v=spf1 a mx ip4:XXX.XXX.XXX.XXX -all

*Replace with your VPS server IP.

Now only your server can send emails from your domain.

If you noticed, Postal will give you an example SPF to copy, and it looks like this:

v=spf1 a mx ~all

This is just an example domain, and you need to change this in the postal config file to match your domain name. How?

Edit Postal config file.

To Edit the POstal Configuration File, we will need to connect to our server using a File manager to make things easy.

So, You can Use WinSCP, a free remote file manager, to connect and edit the files on the server.

Open WinSCP, and Connect to your server using the root credentials. and go to: /opt/postal/config Directory. Then Open the postal.yml file.

Postal yml configuration
Postal yml configuration

Then, right-click and edit the file.

postal domain change
postal domain change

As you can see, just change the example domain with your domain name.

After that, you need to restart postal for the configuration to take effect.

So run this command on your server:

postal restart

And Refresh your web page, you must see now that was replaced by your domain and you can simply copy the SPF record to your DNS zone.

postal spf record
Postal SPF record

Very Nice! ✔️

Now our Server is ready for testing.

Finally! Send a Test Email

Postal has built-in functionality to test sending emails, simply click on Messages, then on Send Message to test out Free SMTP server!

Send a test message


Now you may be wondering how to use this SMTP as a relay to send emails from any email marketing application.

The Answer is simply by creating “Credentials” inside Postal to connect and authenticate to our Free SMTP Server.

Create Postal Credentials to Relay Emails

To create credentials, simply click on Credentials, then Add new Credentials.

For the Type, Select SMTP.

You can also select API if you wanna connect to postal through the API or develop your own application that works with Postal. Read more about the API here.

Enter a User (Anything you want)

And the Key, is the password, you can keep it as “automatically generated

postal free smtp credentials

And that's it, you can now use these credentials in any email marketing application.

Relay a Test Email

Simple, Go to SMTPER.NET and enter your server details as follows:

Test your SMTP
  • SMTP Host: Your Server IP or Domain.
  • Port: 25 or 2525
  • Login: The User You entered in credentials.
  • Password: The User Password.

So, these are the credentials that you can use in any Email Sender Application.

That's it! I hope everything was simple and clear. we finish setting up the Free SMTP Server!

If you have any problems, you can open your questions on

And if you like to get the Full Udemy Course On Build Your Own Cold Email Outreach System – Postal & Mautic, you can enroll now with a Special Limited Time Discount.

Check Also: PowerMTA Mail Server Full Setup Guide ????

Before You Send!

Congratulations! You Setup your own Free SMTP Server using Postal. but before you start sending emails, you have to understand some crucial concepts and follow up on the guidelines to get the best delivery rates and reach the inbox!

Warming Up your SMTP server

When you build a New SMTP Server with a new IP Address, and Before You can Start Sending Your Email Marketing Campaigns, you have to warm up your IP Address.

What is Warming Up IP?

When you have a new Brand IP Address for your SMTP, this IP will have no Reputation on the internet, and ISPs (internet service providers) don't know this IP.

So IP warmup is the practice of building Your Reputation on The Internet by gradually increasing the volume of mail sent with your IP address according to a predetermined schedule.

Example of warming up your server shown in the table below:

Warmup DayEmails To Send

This Table shows a scenario if you wanna reach 1K emails per day with a good reputation. Please refer to my Warming up SMTP Guide for more details.

Also, you can watch my full video about Warming up here:

rDNS (Reverse DNS):

The reverse DNS is called a pointer record and is used to point your IP to your Domain, its the inverse of the regular DNS A record.

So when you call the IP, you will get the name. It is also an essential factor in setting up your mail server and increasing your sending score and reputation.

Learn more about rDNS here:

DMARC (Domain-based Message Authentication, Reporting & Conformance):

It is a Protocol that uses (SPF)  and (DKIM) to determine the authenticity of an email message. 

DMARC makes it easier for Internet Service Providers (ISPs) to prevent malicious email practices, such as domain spoofing in order to phish for recipients’ personal information. 

It allows email senders to specify how to handle emails that were not authenticated using SPF or DKIM. Senders can opt to send those emails to the junk folder or have them blocked them all together.

To understand the importance of DMARC for your Online Business and how to set up, please watch this video:

MX Record

Mail Exchange (MX) records are DNS records that are necessary for delivering email to your address.

In simple DNS terms, an MX record is used to tell the world which mail servers accept incoming mail for your domain and where emails sent to your domain should be routed to. If your MX records are not pointed to the correct location, you will not receive an email.

Avoid Spam Factors

Mainly we have Four main factors the determines your spam score:

  • IP Reputation
  • SPF, DKIM, rDNS, and DMARC.
  • Message Body
  • Email List health.

The first two factors are explained above. we still have Message body and Email List Health.

Message body

Simply is the subject and the content of your email. does it look spammy? does it have any spammy keywords and triggers?? this what determines your message score.

Be sure to avoid any of these while creating your Subject lines and Message bodies.

Check this article on Hubspot, to learn more about spam keywords.

You Maybe Also Interested in this article “How To Land Your Emails In Inbox? The Ultimate Guide!”

Email List Health

Simply it's determined by two things:

  • Bounce Rate: How many emails are valid in your list.
  • Spam Traps: does your list contain any spam traps?

Learn more about spam traps and how to avoid in this video:

And always be sure to validate your email lists and clean it before sending any campaign. check my free online email validation service here.

I think you will be also interested in watching this video:

How to send 100K emails Daily to inbox.

Follow up My Youtube Channel For Daily Awesome new videos about Email Marketing, Digital Marketing, and Online business stuff to Grow Online.

Also, Join My Email Marketing Newsletter to Get exclusive Email Marketing Tips that I share only with my email subscribers.

Optional (IF YOU USE NGINX): Secure with a Free SSL.

SSL certificates are used within web servers to encrypt the traffic between the server and client, providing extra security for users accessing your application. Let’s Encrypt provides an easy way to obtain and install trusted certificates for free.

Connect to your Server using Putty SSH client. and Let's Start!

Step 1 — Install the Let’s Encrypt Client

Let’s Encrypt certificates are fetched via client software running on your server. The official client is called Certbot.

Install Certbot by running this command:

apt -y install certbot

Certbot is now ready to be used. ✔️

Step 2 — Get the SSL Certificate

But, before we get an SSL Certificate, we need to stop nginx service since its using port 80 which certbot will use. so Let's stop it temporarily by running the following comnad:

sudo systemctl stop nginx

Now let's install the certificate, run the following command:

certbot certonly --standalone -d

Replace “” with your domain.

And follow the wizard. Then certbot will issue a certificate for your domain.

Step 3 — Configure the SSL Certificate

After we got the SSL certificate, we need to configure it in our server.

Let's start the nginx service again:

sudo systemctl start nginx

Now, Open WinSCP again to edit some files on our server.

Connect to your server, and go to /etc/nginx/conf.d directory.

In this folder, create a new file and name it: “

Replace “” with your domain.

Then, Simply copy the following code and paste inside the file.

server {
    listen [::]:80;
    return 301 https://$host$request_uri;

server {
    listen [::]:443 ssl;
    listen ssl;
    root /opt/postal/public;
    ssl_certificate      /etc/letsencrypt/live/;
    ssl_certificate_key  /etc/letsencrypt/live/;
    ssl_protocols TLSv1.2 TLSv1.1 TLSv1;
    ssl_prefer_server_ciphers on;

    location / {
       client_max_body_size 50M;
       try_files $uri $uri/index.html $uri.html @puma;

    location /app/assets {
       add_header Cache-Control max-age=3600;

    location @puma {
        proxy_set_header X-Real-IP  $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;

And save the file.

The last step is to restart and enable nginx again. Simply run the following command:

systemctl restart nginx

Then this command:

systemctl enable nginx

And Awesome, Now you can test your secure Postal website!

Good Luck!

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      1. In postal panel its showing me spf verified but when i check on mxtoolbox its not verifying spf record even i send email and check the status in mailbox its showing me neutral

        1. My problem is similar
          For both spf ND dkim
          I tried other mxtoobox alternatives, they all turned out the same

  1. I have this error trying to install postal on my server.
    curl E: Sub-process /usr/bin/dpkg returned an error code (1)
    What’s the cause and how do I resolve it? thank you

      1. Hello Hassan, I am able to setup the server as instructed with out any ish but testing my smtp with, i did not receive the test message to my gmail account instantly. Any reason for that?

        1. HI Esclan,
          soft mail you are getting because your SMTP server is blocked by your smtp server provider. You need to ask your smtp server provider to unblock your port 25.
          like if you purchase the hosting from need to write to the support to unblock the port 25. they will ask some details and once you share..they will immediately unblock the port 25. But don’t tell them you are going to do the cold mailing.

  2. Hi Hasan
    I’m facing this issues:
    “We didn’t find a server (A Record) behind your hostname”(
    As I’ve updated the postal.yml and updated with my domain name and A record has been updated with my IP. But I’m unable to identify why this error is showing? Kindly guide and help me on this please?

  3. hi hassan can you tell that how can i monitor my open click rate and i am using your super emailsender so how can i add an unsubscribe link to that also can you make a tutorial on mailwiz or mautic on unsubscribe link and monitoring open click rate. i watched your recent video the 1 million inbox case study so i have a project on 80k cold emails per week i am trying to get 10/10 score but seem to get this spf error but i have set these records. also if you can help me how to get open rate that would be nice. my list is also validated using your super email validator on my windows smtp.
    in the end thanks for reading this long msg
    i learned alot from you thanks
    till now i have earned 160$ in last 15 days by sending some small campaign and validating emails and i just started watching you.
    now i am getting some big campaign then previous. hope you can provide support on open rate and unsubscribe link.

      1. Ok so now i am kind of an beginner expert i think. but still i learned from you. i created a cpanel on digitalocean using your video and have a 10/10 score no i also installed mailwiz on it and doing warmup its day 6 today there are bounces but i purchased an email service and setup that smtp as my bounce handler on mailwiz. i am getting all stats also now on mailwiz open rate bounce rate. it is also showing everything i require. from day 1 to day 6 of warmup my open rate is increasing and people are also unsub form my list that was my purpose i am sending welcome mails with unsub mails.
        the results are looking good thanks for everything.

        1. What you mean by i purchased an email service and setup that smtp as my bounce handler on mailwiz.?
          Which service you are using?

    1. Hi Muhammad Junayed,
      Are you using Digitalocean? It is bcoz DO blocks port 25 for new accounts and your SMTP cannot able to maintain a connection between your SMTP and receiving SMTP.

      I created a ticket to open port 25 to DO Support team and they said to me that they don’t allow port 25 in any case. So don’t waste your time researching bcoz I researched a lot. Hope there will be a solution for that.

      Awais Shah
      [email protected]

  4. Hi Hasan, How can I connect Postal with other SMTP Servers like Google’s SMTP using port 587 or another port (expect port 25).

    Digitalocean doesn’t allow port 25 on New user account.

    Plz, reply.

      1. us vultr..they will allow you to use smtp server …you need to write them in support to unblock the smtp server…they will ask some details and for the details how much email you will send on daily basis and reason, just give them 500 or 300 emails per day and it is for the inner email server for my company..they will surely allo that ..

  5. How do you connect to Postal from Sendy? I have tried everything and can’t get it to connect. I have followed this guide faithfully from start to finish.

  6. I am having this issue with the last setp.

    Cannot get real path for ‘/etc/nginx/conf.d/ {
    listen [::]:80;
    return 301 https://$host$request_uri;

    server {
    listen [::]:443 ssl;
    listen ssl;
    root /opt/postal/public;
    ssl_certificate /etc/letsencrypt/live/;
    ssl_certificate_key /etc/letsencrypt/live/;
    ssl_protocols TLSv1.2 TLSv1.1 TLSv1;
    ssl_prefer_server_ciphers on;

    location / {
    client_max_body_size 50M;
    try_files $uri $uri/index.html $uri.html @puma;

    location /app/assets {
    add_header Cache-Control max-age=3600;

    location @puma {
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto https;
    No such file or directory.
    Error code: 2
    Error message from server: No such file

  7. Hello hassa been an honor following your letures, you’ve been an amazing value to the community.
    But I have some issues with my Dkim record, I followed all the steps on the blog but the dkim seams to return error on mxtoobox but it shows verified on postal, as a result of this my email ends in spam as it has no valid domain signature, plz what do I do

  8. I am getting this error “530 From/Sender name is not valid” The domain is already added to the panel. Do you have a solution for that ?

  9. can you install Mautic on the same server on which you have postal installed . IF yes what configuration you need to make

  10. Hi, Thanks fo your guidance. It help me a lot. When I testing SMTP server on Free Super Email Sender I get a error “A connection attempt failed because the connected party did not properly respond after a period of time, Or established connection failed because connected host has failed to respond XXX.71.236.XXX:25”
    Please see this screenshot-

  11. Hi I have followed all the steps but still my mail server gives an error plus if I test it goes to spam in my gmail.

    Please could you assist ?

  12. Hi,
    I have problem with delivery.
    Problem is with, – HARD FAIL.
    @gmail – are delivery OK.
    But if I send from my personal account (gmail) to this hotmail or yahoo mail- mail is delivery OK. without problem.
    It is big problem because now my IP adress (domen) on Blacklist!:(

  13. Hi,
    Thank Hassan for, Nice tutorial, I have installed postal in ubuntu [aws lightsail] successfully. but it is not opening in browser. what could be the issue?

  14. hello hassan, I followed your blog and able to install postal on my server. when I tried to send email from postal inbuild send option to my gmail it works, but when I am trying to use postal smtp credentials to test the server from gmass smtp test tool its is giving me “ERROR: No connection could be made because the target machine actively refused it”. Need your help asap. thx

      1. how? I believe i have got proper ssl certificate from running cert bot. my website is secure now. still facing same issue. can you please explain a bit how to fix this issue. this is my first project. your help will be highly appreciated. thx hassan

      2. Still waiting for you reply Mr. Hassan. ichecked everything I am not able to find out what the problem could be. In gmass smtp test I am getting “ERROR: No connection could be made because the target machine actively refused it” this error

  15. Hello,

    I followed your video to install postal mail server smoothly till sending test in say “SMTP send error The operation has timed out.”
    So I guess there was issue with SPF , Then I used Winscp to changed “spf_include:” into “spf_include:”. Next step I retart the droplet and refresh postal webpage, it occued “502 Bad Gateway nginx/1.14.0 (Ubuntu)” !!!
    What should I do now, I am stuck here.

  16. Hello H-EDUCATE
    My Postal server has been installed, and the domain name resolution is all ticked, but the test mail sending timed out, please help me, thank you

  17. Hello Hassan,
    Your guide to create SMTP server has really been helpful and i have been successful to create it as well. But I am facing 2 small issues so I was wondering if you could help:-

    1> I am unable to use TLS on server.
    2> I am able to send the mails from Postal send mail feature under messages menu but unable to connect or send emails through SMTP Relay credentials (

    And if possible please do create a detailed tutorial or course on Postal as well.

  18. SPF record doesn’t seem to recognize the changes
    For the name it gives even when I put @
    Have tired both these values nothing works
    “v=spf1 a mx ~all”
    “v=spf1 a mx ~all”


      1. I have followed your video in that whatever setup for postal was there till creating user for postal have manged. Other than this have not edited anything on postal.yml

    an excellent knowledge and info provided ,
    as you know i am very new in effiliate program just in learning mode.
    i near to finish wordpress training. but i love as effiliater. i will remain connect with you try to learn from you .
    your best wisher

  20. Hello Hassan,

    First of all thank for good video and article. I am receiving emails but in the spam folder. I am checking my server score using but I got only 5.2/10.

    I changed host and other records in postal.yml file as well but still getting error.
    I have attached screenshots. Please take a look and guide me. I am using free domain using freedom for testing.

    protocol: https



  21. all things i did.. but i think there are more things to

    but how do i connect postal with mailwizz.
    hostname: i change on postal.yml
    username and keys: as password
    but when i validate it
    My SMTP Port 25 is open :
    SMTP Reverse DNS Mismatch Reverse DNS does not contain the hostname
    SMTP Banner Check Reverse DNS does not match SMTP Banner
    SMTP TLS Warning – Does not support TLS.


      1. thnx for the reply. bounces isnt the issue now. i cant validate it
        always get this error when i connect my postal mailwizz
        i did all and when i send msg from postal i get it on spam its all good but validation doesnt work

  22. i cant validate it my postal to mailwizz
    always get this error when i connect my postal mailwizz
    Cannot send the confirmation email using the data you provided.
    Here is a transcript of the error message:

    i did all and when i send message from postal i get it on spam its works good but validation doesn’t work
    also if i send email to my server it doesn’t come in incoming message

  23. hello hassan ,nice course,i followed the instruction like was stated in your video,all my records are ok ,but when i decided to sent a test email,i has been pending for more than 5 hours,does this mean port 25 has been blocked?

  24. Hi Sir Hasan,

    Can I install Postal SMTP on Webmin (Virtualmin) Virtual Server as a non-root user?
    I am facing this problem while installing postal SMTP on virtual server

  25. Hello, i installed and everything is perfect. i even sent a test mail and it worked. My question is this:
    How do i connect this server to a software like Send Blaster?

  26. Hi Hasan
    I’ve been following you from long time and I just decided to make a SMTP server finally.

    I setup my SMTP server just by following your article and videos,so all thanks to you. I’m really grateful.

    But , the only thing not set on my domain properly is SPF record.

    Are you suggesting we set SPF record twice one with v=spf1 a mx ip4:XXX.XXX.XXX.XXX -all
    the other with v=spf1 a mx ~all .
    I’m a bit confused and can’t this one thing right.

    Can you help or clarify?I would be grateful.

    Thank You band kind regards
    Love from India


  27. Hi Hassan,

    Have you figured out how to monitor and mark bounces with Mautic and Postal? I have read your comments in Github on the topic and wondered if you have made any progress? I have tried all that I can think off with no success.

  28. The postal server has suddenly stopped… I’m sending mails but the emails are added to suppression… Even when those ids are genuine. What to do? Everything was working fine all this while. Please help.

  29. I have tested emails inside postal and it is successfully going to my gmails spam folder. But when I try to connect it with my mailwizz via API it s showing error like cURL error 6: Could not resolve host:

    Please help

  30. Hello Hassan Sir, with the help of your blog I have created mail server with postal and everything is fine, but when I am testing sending score I am getting 9.9, The major problem is related to the DKIM records, Its showing the problems like this:

    Spam Assassin thinks you can improve Score: -0.1

    -0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid
    This rule is automatically applied if your email contains a DKIM signature but other positive rules will also be added if your DKIM signature is valid. See immediately below.

    0.001 SPF_PASS SPF: sender matches SPF record
    Great! Your SPF is valid

    -0.01 T_DKIM_INVALID Your DKIM signature is not valid
    Have a look at our DKIM test below to know why, this may be a false-positive

    Except this everything is good sir,

    Please check those problems and suggest me the required steps to
    resolve those problems.

    Thank you sir,

    Best Regards.

  31. Hi Hassan,

    Have you figured out how to monitor and mark bounces with Mautic and Postal? I have read your comments in Github on the topic and wondered if you have made any progress? I have tried all that I can think off with no success.

    Thanks 😉

  32. hello is there any wordpress smtp plugin like wp mail smtp but i wanted to use postal api to connect with wordpress directly for smtp as i seen issues connecting postal with wp mail smtp any plugin u can recommened for adding postal API for wordpress smtp for sending emails from wordpress

    1. Hello Friend,
      The credetials are the same the you use in putty (root and password).
      For more questions, please post on

  33. Hi, Hassan! I watched your video on postal SMTP and Mautic, I configured Postal and Mautic on Digital Ocean (in two separate droplets). I also configured the DMARC, SPF, DKIM, MX.. and also verified the dns with google post master. Now I’m getting a email test score of 9.6, Checked with MX Toolbox, all the records are ok but still my e-mails campaigns are landing on the spam folder. Please help.

  34. Done everything from Your video but, when I try to set “postal make-user” it says:

    Usage: postal [-m maximum-message-size] [-M minimum-message-size] [-t threads]
    [-c messages-per-connection] [-r messages-per-minute] [-a]
    [-b [no]netscape] [-p port] [-[z|Z] debug-file]
    [-s ssl-percentage]
    [-L] [-l local-address] [-f sender-file]
    smtp-server user-list-filename

  35. Hi. How can I post questions on the forum? I have a problem with Postal.

    I have followed your steps on the video and the blog post on how to configure Postal. I have tried with Contabo and Digitalocean IP address, but it doesn’t work. I get an error. Can you check if there’s any problem with the Curl code ??
    Please, I really need help!

  36. After completing warmup of 1000 emails on the 8th day, the 9th day will I follow again the same schedule from the beginning of the 1st day Please explain

  37. Dear Hasan
    Thanks for this nice tutorial. Is it possible to create IP Rotation ( Using IP POOL) in postal smtp server like PowerMTA for same domain.

  38. Hello sir, thanks for your post that explains how to create Postal SMTP!

    i followed ur and everything went Just great till the last part! when i do test sending email it failed. All emails I send are pending

    I use VPS Contabo

    I contacted support Contabo open port 25.
    “does not restrict any port access. Any port can be freely used for whichever application.”

    why test email send failed

  39. Will this work with your Super Email Sender if we selected SMTP Server as a delivery service?
    Basically I am using a normal license and I am not able to choose other delivery services which are Google and POSTAL API.

  40. Thank you so much Hasan. I need your help. I want to use Apache instead of Caddy in Ubuntu18.04. Is it possible? Because, I want to run Postal Webclient and Mailwizz under same server. It would be euphoric for me if you reply. Thanks you.

  41. I try to run the command to install Docker but it tells me that “-curl” and “-sudo” not found I appreach it the support

  42. Hey Hasan, You said that we need to make changes in postal.yml and made the changes but after that I want to know how to restart. Plz tell that where I need to enter this command “postal restart”. Does I need to enter this command in PuTTy.

  43. Hello, I have followed your tutorial to install postal SMTP, everything is working fine and installed properly but I am unable to get Postal Web Interface. Is there any reason why its not working?

  44. Hi Hasan,
    I hope you are doing well.
    I have a vps server on vultr with Cyberpanel installed and have 3 websites on this server. How can I install Postal on this server? Please let me know. It will help me a lot.

  45. please i need the command on PUTTY
    i have so hard to get it on your YouTube but i could not see it
    please send me the command

  46. I’m getting this error
    N: Skipping acquire of configured file ‘main/binary-i386/Packages’ as repository ‘ bionic InRelease’ doesn’t support architecture ‘i386’

  47. hello hassan,
    nginx.service: Control process exited, code=exited, status=1/FAILURE
    Dec 14 15:16:15 systemd[1]: nginx.service: Failed with result ‘exit-code’.
    Dec 14 15:16:15 systemd[1]: Failed to start A high performance web server and a reverse proxy servrice

    what should i do ? thanks

  48. Greetings! I have a simple question that is confusing me, can you clear my confusion regarding these issues, please. If I use Amazon AWS SES service for my email marketing purpose. Then, do I still have to install postal or other servers?

  49. root@node:~# sudo systemctl stop nginx
    Failed to stop nginx.service: Unit nginx.service not loaded.

    how tto clear this error and install ssl certifacte

  50. Hello Hassan,

    I watched the video and was very excited that with one command you configure and install postal on your server, and as per your instruction I checked the description of the video but instead of a command there was a link to this article, here I am seeing numerous commands and I am very nervous to proceed. I would really appreciate if you can share that simple command for installation with me.


      1. The initial commands are so so confusing..
        -sudo apt-get install \
        apt-transport-https \
        ca-certificates \
        curl \
        gnupg \

        is this one command or several different comands?

  51. This is just a appreciation post. Thank you for explaining everything so well. I understand everything much better. Keep up the good work, I’m a happy subscriber!

  52. Hello Hassan,
    Thanks for this guide.

    I want to ask some questions as regards your full course.

    Can postal be install via WHM/Cpanel instead Command Line Interface using putty?

    Does your full course cover how to install Postal Via Cpanel?

    Can we run an email application like mailwizz and Postal on the same domain?
    If yes which one of them will be in the main domain? or can both be at sub-domain


    Let me know if your course cover all these

  53. Hello Hasan,

    I have learnt many new concepts from your video. God bless you for your direct and indirect support to humanity.

    I would like to request you to advise me some other companies for SMTP Mail Server configuration for sending emails.

    I created account on Digital ocean following your link given in the description. To the highest surprise, they debited $5 and then locked the admin. I do not trust this company as this is happening second time.

    Also, please clarify me if I can use the same SMTP server for sending emails by MailWizz?

    Looking forward to your support.

    Thank you.
    Best regards,

    Sumit Sinha

  54. Hello, please I so much enjoy your tutorial, how do I receive emails if users respond to the bulk email sent via postal SMTP server. I really need this please.