Dear all,
I have a mail server based on a CentOS 5.3 machine with postfix.
Most of our users are on LDAP (on localhost) but we also have some local users and we are using PAM for authentication.
Sometimes emails are not delivered to an user (happens either with users on LDAP or local users on shadow) with error "unknown user" (sometimes the error comes from smtpd and sometimes from procmail when writing to an users' folder):
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Apr 23 16:00:37 mail postfix/smtpd[6707]: D62A676856C: reject: RCPT from unknown[116.23.241.165]: 550 5.1.1 xxxxx@astro.up.pt: Recipient address rejected: User unknown in local recipient table; from=DianncartePickens@sunshinemillions.com to=< xxxxx@astro.up.pt > proto=SMTP helo=<b826affb8c4a402>
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May 4 05:53:08 mail postfix/local[13781]: E33F776882D: to=xxxxx@astro.up.pt, relay=local, delay=0.03, delays=0.01/0/0/0.02, dsn=5.1.1, status=bounced (user unknown. Command output: procmail: Unknown user "xxxxx" )
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It seems that sometimes the system (postfix? procmail? ???) can't retrieve user information.
Any ideas on what might be causing this?
Thanks!
Cheers,
Manuel Monteiro