[BlueOnyx:25910] Re: sendmail issue with fairly new 5210R server

[Larry Smith]

Michael,

  Got around to trying your suggestion to switch
to Postfix (from sendmail ) on this server.  First
off get error (warning):
"Do not list domain XXX.domain.tld in BOTH mydestination 
and virtual_alias_domains" where XXX.domain.tld is the
name of the server itself.  Commented out the server
name from /etc/mail/local_host_names cleared this error
but sure the next change of any sort will put it back.

Second, get the error (warning):
"connect to Milter service unix:/var/run/milter-geoip.sock: Permission denied"
Have not figured this one out.  Not sure if it is hurting anything
or not.

Also got a few errors on file being newer than their DB (vsite_ssl.map)
but ran postmap on this fixed it.

Watching to see if I get any more "User unknown" for existing accounts.
Got one again this morning with sendmail which prompted me to go ahead
and try the change to postfix.

-- 
Larry Smith
lesmith at ecsis.net

On Fri January 6 2023 11:06, Michael Stauber wrote:
> Hi Larry,
>
> >    Yes, in several of the cases it happens to be two domains
> > that I host (on separate BlueOnyx boxes) so I can verify
> > the error from both servers - a "User unknown" for an
> > existing user (that is not over quota for user or site).
> > And it is only this one 5210R that is doing it.
>
> Do you by chance run a setup where you have www.company.com on one
> server and mail.company.com on an another? There is nothing speaking
> against that and I use that setup myself.
>
> However, when you email user at company.com from the box that has
> www.company.com you have to be careful that it doesn't try to make a
> local delivery. This is where /etc/mail/local-host-names comes in. It
> should only have entries for email aliases of Vsites or Vsite FQDNs that
> directly receive email at username at fqdn.
>
> If these are 5210Rs and they use Sendmail, then try to switch the MTA to
> Postfix instead and see if that makes a difference.
>
>  > Everything will work fine for hours, then suddenly
>  > a single user on this domain will get the "User unknown"
>  > error and that message is bounced
>
> The Sendmail/Postfix configuration and alias setup is static and it
> doesn't change on its own unless you add/remove a user or Vsite.
>
> So if *that* (aliases, Sendmail/Postfix config) were an issue? You'd
> have the problem *all* the time. Not once in a while or sporadically. It
> would always work or always fail hard.
>
> The sporadic nature of the issue makes me suspect it might still be a
> DNS issue. Maybe you run or use multiple DNS servers and one has bad or
> outdated info? Then it might work as long as the "good" DNS server
> answers, but fails when the "bad" one is handling the replies.
>
> I've had such an issue recently with the BlueOnyx mirrors and it was
> driving me mad until I realized one of my three DNS servers hadn't
> automatically update the zone in question.