MIAB + Additional VPS (relay email not working)

[Corvin]

Hello,

I setup MIAB on a VPS for my primary domain example.com
I also setup a secondary VPS for my other domain, example2.com (since this is the one I want to use as a webserver).

I am using external DNS (from Digital Ocean) setup using the instructions from my box for the primary domain.
I am using the external DNS for the secondary domain however pointing to the IP of my secondary VPS and with the MX record pointing to the MIAB VPS.

I managed to add users in MIAB for my example2.com domain and I am able to successfully send and receive emails with one exception: I am not able to send out any kind of email (form my secondary server) such as the ones sent by Wordpress or CSF firewall (I believe that Wordpress is using PHP Sendmail and CSF is using EXIM).

Since the primary VPS contains MIAB and is fully setup, my secondary VPS has it’s MX entry pointing to MIAB, how can I resolve the issue with the emails sent out (and failed) by Wordpress and CSF?

(I am not sure if I would not hit the same roadblock even when MIAB would handle the DNS - using glue records)

Thank you,

[Corvin]

The title however is misleading: it is not a relay issue since the relay itself is setup for postfix.
The issue is that I cannot figure out how to configure the webhost (Wordpress and CSF) to send emails using MIAB smtp.

Sorry about the confusion

[ANC]

I think this is the WordPress plugin you will want:

WP Mail SMTP by WPForms

or perhaps this one:

Easy WP SMTP

Let us know if it works!

[Corvin]

Thank you for sharing those plugins.

None of the SMTP plugins actual works.
I input the SMTP server using the hostname of MIAB, the full email address as user and my password and it cannot connect.
One of the plugins was giving me a “connection timed out”.

Since I’m using SSL I just need to make sure that CSF is not locking down the port.

I will recheck CSF at least to rule out the firewall.

Thank you!