[Mailman-Users] 'Undelivered Mail Returned to Sender' error when using an e-mail from a domain co-hosted with the one used for Mailman lists

[Mark Sapiro]

On 04/25/2014 03:25 AM, Jacques Setton wrote:
> 
> 1) Selected Sequence from /var/log/maillog  
...
> Apr 21 02:49:56 vps12345 postfix/smtp[9414]: F030911C008:
> to=<mailman-request at domain.org>, relay=127.0.0.1[127.0.0.1]:10024,
> delay=0.73, delays=0.26/0.01/0/0.46, dsn=2.0.0, status=sent (250 2.0.0 from
> MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as 9F72D11C00A)
> Apr 21 02:49:56 vps12345 postfix/smtpd[9419]: disconnect from
> localhost.localdomain[127.0.0.1]
> Apr 21 02:49:56 vps12345 dovecot: auth: sql(mailman-request at domain.org):
> Unknown user
> Apr 21 02:49:56 vps12345 postfix/pipe[9420]: 9F72D11C00A:
> to=<mailman-request at domain.org>, relay=dovecot, delay=0.04,
> delays=0.01/0.01/0/0.02, dsn=5.1.1, status=bounced (user unknown)


Delivery to Mailman is via aliases. The dovecot LDA does not use your
aliases. Delivery to Mailman must be via the local LDA.

Something in your Postfix configuration is telling it to relay this
particular mail via the dovecot transport rather than the local
transport. That's why it bounces. The question is what's causing it.

I suspect it has to do with two things in your Postfix configuration:

local_recipient_maps = unix:passwd.byname

and

virtual_transport = dovecot

By default, local_recipient_maps includes $alias_maps, and I *think* it
should in your case. Why this lack would cause Postfix to use the
virtual_transport rather than local in just this one case is really a
question for postfix-users at postfix.org or some other Postfix resource,
but you might try

local_recipient_maps = unix:passwd.byname $alias_maps

or simply removing that line from main.cf and see if that helps.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan