This most probably is not a vpopmail problem, but a chkuser one.
The support page of chkuser
points to this mailing list, so that's why I'm posting this here.
The mail server in question runs:
Messages sent to existing and not overquota users on this server
randomly (as far as I can tell) are rejected with this message:
Remote host said: 553 sorry, that domain isn't in my list of allowed
rcpthosts (#5.5.3 - chkuser)
I've checked and double checked that the user exists and there was no
typo when entering the destination email address.
Sending again after a while to the same user ends up with the message
into his mailbox without any issues.
The server's /var/log/qmail/smtpd/current log file shows this about the
2009-07-24 12:28:19.035629500 CHKUSER rejected relaying: from
<sender's_email_address::> remote <remote_mail_server:unknown:remote_ip>
rcpt <valid_u...@mail.domain.tld> : client not allowed to relay
The mailboxes on this machine are all respecting this pattern:
The /var/qmail/control/me file lists this: mail.domain.tld, which is
also the MX for domain.tld
/var/qmail/control/rcpthosts lists both domain.tld and mail.domain.tld
/var/qmail/control/virtualdomains shows domain.tld
/var/qmail/control/locals shows only mail.domain.tld
/var/qmail/control/defaultdomain only shows domain.tld
What could be wrong, but most of all, why is the error occurring only
rarely (but often enough to be annoying)?
Thanks in advance for any answers you might be able to provide.