Thank you, Yousef.
Firstly I recommend you to watch this video to show you the Email marketing Path and which course you need.
Click here to watch the video.
Then, Postal allows you to create Multiple SMTP servers within 1 VPS server.
But as a start, you will not need more than 1 SMTP for cold emails.
The course will help you understand and configure postal and domains. then you can connect with the mailing app to send your campaigns like Mailwizz or mautic which is explained also in the course.