Configuring Mailcow to Use Dedicated IPs for Multiple Domains

just4lmgame

Hello,

I am currently running a Mailcow setup on Ubuntu 22.04 with four public IP addresses. I aim to host four different domains on this server and ensure that each domain uses a dedicated IP for sending outbound mail. My goal is to configure this without disrupting the existing Mailcow configuration or mail delivery functionality.

I am seeking guidance on the best approach to achieve this. Specifically, I am looking for advice.

Thank you for your assistance!

Best regards,
[LM]

ETNyx

If you are not an expert into mail stack and how to configure it, I assume you are not, cause you are asking, than i would advice to make 4 separate mailcow instances to handle your domain per IP separation.

If you insist on one instance, you will need to make pretty non-standard configuration change in your postfix start whit master.conf spin up multiple smtp services like this

(do not copy&paste, it will break something)

domain1 unix -       -       n       -       -       smtp
      -o syslog_name=mail.domain1.com
      -o smtp_helo_name=mail.domain1.com
      -o smtp_bind_address=1.1.1.1

domain2 unix -       -       n       -       -       smtp
      -o syslog_name=mail.domain2.com     
      -o smtp_helo_name=mail.domain2.com
      -o smtp_bind_address=2.2.2.2

and remake transport maps somehow like

@domain1.com domain1:
@domain2.com domain2:

and possible much more, it can be done, but just don’t.