All mail Queued in Postfix due to connection timed out

SYSTEM INFORMATION
OS type and version Debian 10
Virtualmin version GPL

All of the e-mails sent via Wordpress are getting “connection timed out” errors, they’re using “nameofuser@hostname” as the “From” address, I thought it might be because of the lack of proper SSL certificate on the hostname, but even after fixing it, it’s still failing.

What should I do to fix it? How do I debug those Issues?

Thanks in advance!

I found out that it’s because Digital Ocean is blocking port 25, and they recommend to set up mail through a relay like mailgun/sendgrid.
How do I configure Mailgun to relay all mail sent from virtualmin servers? Do I have to set up everything manually?

If mail is getting queued because port 25 is blocked then your initial problem report was misleading: it is not just mail sent via WordPress which is not being sent out; all mail from that server is not being sent out.

Anyway, you don’t have to set up everything manually if you use Mailgun. You have to set up almost everything manually if you use Mailgun. See

Also see smarthost [#10919] | Virtualmin

And also Free smarthost / mail relay to work around port 25 block by VPS host

I managed to set up mailjet as a smarthost and to send emails through it via the port 587, but I then noticed that the server isn’t accepting e-mails, upon inspecting mail logs, the mails do get onto the server, but something doesn’t connect on postfix server and then the e-mail fails to be received