Nikolaos Milas:
> On 17/2/2017 4:12 ??, Wietse Venema wrote:
>
> > You missed the preceding warning that says why.
> >
> > - The server greets with the same hostname (in the 220 line)
> > as the client wants to use (in the EHLO cdommand).
> >
> > - The server IP address matches $mydestination or $proxy_interfaces.
>
> Thanks Wietse,
>
> I didn't change anything, but it has now started working properly.
Again, please look for Postfix warnings that say "host greeted me
with my own name" or similar. If there are none then there was a
problem where DNS resolved a destination to a hostname with an IP
address that matches the mydestination or proxy_interfaces setting
of the sending MTA.
Wietse
