No Incoming Mail

I just setup a new VPS on Cent OS 8 Stream and installed CWP.

I used the CWP to CWP to transfer accounts from the old VPS. Switched the Nameserver IP to point at the new VPS.

Websites are all loading fine and email from previous server. However, I have just realised new incoming emails are not being recieved.

I have reviewed the log and found the following error:

 Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Permission denied!

So I added the following to /etc/dovecot/dovecot.conf

service stats {
    unix_listener stats-reader {
        user = vmail
        group = vmail
        mode = 0660
    }

    unix_listener stats-writer {
        user = vmail
        group = vmail
        mode = 0660
    }
}

The error in the log is now gone but the emails are still not arriving in inboxes still. Worryingly they are not sat in queue either.

I have tried reboot and rebuilding mail server.  However, each time I rebuild mail server it loses the setting added above and I get the error mentioned about again. Add the same fix and problem remains.

Need to resolve urgently so any guidance gratefull recieved.

Ok. Turns out incoming mail is working. I was using the Mail Explorer to check inboxes to see email has been delivered.

It looks like there is a lag and mail doesn't immediately appear in Mail Explorer. When I logged in via RoundCube webmail the emails had arrived.

Although the unix_listener stats-writer error still remains everytime I rebuild the mail server. Not sure if that just an issue for me or all.