Postfix sending to A not MX

[Robert Heller]

At Sun, 27 Feb 2022 14:22:49 -0600 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> On 2/27/22 1:56 PM, Robert Heller wrote:
> > At Sun, 27 Feb 2022 13:39:16 -0600 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> >
> >>
> >> On 2/27/22 12:42 PM, Robert Heller wrote:
> >>> At Sun, 27 Feb 2022 08:33:15 -0800 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> >>>
> >>>>
> >>
> >> [snip]
> >>
> >>
> >>> It looks like you might not have a working DNS server.
> >>>
> >>
> >> I'm a little surprised that postfix uses DNS at all given the following
> >> line in the main.cf file:
> >>
> >> disable_dns_lookups                 = yes
> >>
> >> I don't run postfix, so maybe that setting does something other that the
> >> more obvious interpretation of its name.
> >
> >  From postconf(5):
> >
> > disable_dns_lookups (default: no)
> >         Disable DNS lookups in the Postfix SMTP and  LMTP  clients.  When
> >         disabled,  hosts  are looked up with the getaddrinfo() system
> >         library routine which normally also looks in /etc/hosts.
> >
> >         DNS lookups are enabled by default.
> >
> >
> > Postfix *does need* to do a DNS lookup to find MX records...  If DNS lookups
> > are disabled, I suspect Postfix can't do that, which is probably the OP's
> > problem, if he in fact has that setting (and why would he have that setting
> > for a Postfix server sending mail directly out to the Internet).  The only
> > reason to turn this setting on would be for an Intranet ([Office] LAN only)
> > mail server or one using a "smart host" (forwarding everthing to an uplink
> > relay).
> >
> > I don't have that setting and am running with the default (no) on my mail
> > server (running Postfix).
> >
> >
> 
> Well that's what I kinda thought, but I was a little confused given the
> log output. Thanks for the verification.
> 
> I guess next step would be for OP to disable that setting (=no), restart
> the daemon and see if that fixes the problem.

Just deleting or commenting out the line will do.

> 
> --
> Keith
> 

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