Solved via
https://forum.proxmox.com/threads/smtp-banner-check-reverse-dns-does-not-match-smtp-banner.101161/
and
https://forum.proxmox.com/threads/smtp-banner-check-reverse-dns-does-not-match-smtp-banner.101161/
On the first node:
1. cp /var/lib/pmg/templates/main.cf.in /etc/pmg/templates/
2. add this before the banner line in /etc/pmg/templates/main.cf.in :
[% IF dns.hostname == '
hostname server 1' %]
myhostname =
FQDN-server-1
[% END %]
[% IF dns.hostname == '
hostname server 2' %]
myhostname =
FQDN-server-2
[% END %]
3. Make sure this line is correct:
smtpd_banner = $myhostname [% pmg.mail.banner %]
4. Comment out this line:
#myhostname = [% dns.hostname %].[% dns.domain %]
5. Repeat steps 1-4 on the second node.
6. In the GUI, Configuation --> Mail Proxy --> Options --> SMTPD Banner
Make sure the hostname is not present. The default is something like ESMTP Proxmox
7. Back to the CLI, issue this command: pmgconfig sync --restart 1
8. Review /etc/postfix.main.cf on the first node and look for the line beginning with myhostname=
This should reflect the FQDN for node 1
myhostname =
FQDN-server-1
9. Repeat step 8 on the second node. It should reflect the FQDN of the second server.
myhostname =
FQDN-server-2
Test an email and review the headers to confirm the helo statement is correct
