RESOLVED - Not receiving email from other domains (including gmail)

I have Virtualmin setup on my VPS with Ubuntu 18.04. I have one virtual server on the system and I added an email user in that domain

I’m using Thunderbird as my email client to send and check mail. This is configured to receive POP3 on port 995 and send with SMTP on port 465.

Using Thunderbird I can send email from the account I created to both that same account and also a different (gmail) account and they are received without a problem.

But when I send replies from those emails, the reply from the same account arrives without problem but the reply from the gmail account hasn’t been received. Why does one work but the other doesn’t?

Are the MX DNS records for the domain pointing at the VPS? Firewall allows connections?

Did you look at your logs? Can you see connections from gmail? Can you post logs from /var/log/mail.log? Please put them in code tags (see the more information about text formats link below the reply box).

The MX record points to I don’t think there’s a firewall. At least I didn’t set one up. I did set iptable rules for ports 80, 443, 10000, 995 and 465. My installation of Virtualmin is in a Linux container (LXC), hence the need for the iptable rules.

In the log I found:
Aug 9 23:07:41 inglesnobrasil postfix/smtp[10955]: connect to[2607:f8b0:4003:c14::1a]:25: Network is unreachable
Aug 9 23:07:41 inglesnobrasil postfix/smtp[10955]: A9D932281A:,[]:25, delay=2.3, delays=0.42/0.02/1.5/0.38, dsn=2.0.0, status=sent (250 2.0.0 OK 1565392061 b11si47955068oii.95 - gsmtp)

Aug 9 23:24:28 inglesnobrasil postfix/smtp[12278]: connect to[2607:f8b0:4003:c13::1b]:25: Network is unreachable
Aug 9 23:24:29 inglesnobrasil postfix/smtp[12278]: 38AD22277F:,[]:25, delay=2.3, delays=0.44/0.01/1.5/0.36, dsn=2.0.0, status=sent (250 2.0.0 OK 1565393069 e16si808371oti.216 - gsmtp)

I can post all of the log file if you want, but it’s 455 lines.

One of your problems appears to be that your network or server doesn’t support (or is improperly configured for) IPv6:

connect to[2607:f8b0:4003:c13::1b]:25: Network is unreachable

This could be a problem with (among other things) the network configuration and/or the firewall configuration.

As for not being able to receive mail, is port 25 on your server open to incoming connections?

Thanks, Richard.

I set up an iptables rule for port 25 and now I’m receiving the emails from gmail and other sources.
Thanks again.

My pleasure. I’m glad it was that easy. :slight_smile: