It is obvious you run both Sendmail and Postfix, ending in trouble. The sendmail binary (which is a symlink) still points to Sendmail, though you seem to have configured Postfix as you system's MTA. > I have been careful to re-map transports and restart postfix after any > changes to the config files. The following from maillog may shed some > light as to where the problem lies: > > Aug 22 14:02:11 borg sendmail[1711]: p7MD29Lf001711: from=anne, size=6877, > class=0, nrcpts=1, msgid=<201108221302.p7MD29Lf001711 at borg.xxx.lan>, > relay=root at localhost > Aug 22 14:02:11 borg postfix/smtpd[2067]: connect from > borg.xxx.net[127.0.0.1] > Aug 22 14:02:11 borg postfix/smtpd[2067]: B4693A377C: > client=borg.xxx.net[127.0.0.1] > Aug 22 14:02:11 borg postfix/cleanup[2070]: B4693A377C: message- > id=<201108221302.p7MD29Lf001711 at borg.xxx.lan> > Aug 22 14:02:11 borg postfix/qmgr[1499]: B4693A377C: > from=<anne at borg.xxx.lan>, > size=7487, nrcpt=1 (queue active) > Aug 22 14:02:11 borg sendmail[1711]: p7MD29Lf001711: to=anne at xxx.org, > ctladdr=anne (500/100), delay=00:00:02, xdelay=00:00:00, mailer=relay, > pri=36877, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (Ok: queued > as > B4693A377C) > Aug 22 14:02:11 borg postfix/smtpd[2067]: disconnect from > borg.xxx.net[127.0.0.1] > Aug 22 14:02:12 borg postfix/smtp[2071]: B4693A377C: to=<anne at xxx.org>, > relay=mailhost.zen.co.uk[212.23.3.98]:25, delay=0.43, > delays=0.09/0.02/0.15/0.18, dsn=5.0.0, status=bounced (host > mailhost.zen.co.uk[212.23.3.98] said: 550-Verification failed for > <anne at borg.xxx.lan> 550-Unrouteable address 550 Envelope Sender: Domain > must > resolve in DNS! (in reply to RCPT TO command)) > Aug 22 14:02:12 borg postfix/cleanup[2070]: 2EB94A371B: message- > id=<20110822130212.2EB94A371B at borg> > Aug 22 14:02:12 borg postfix/bounce[2072]: B4693A377C: sender non-delivery > notification: 2EB94A371B > Aug 22 14:02:12 borg postfix/qmgr[1499]: 2EB94A371B: from=<>, size=9481, > nrcpt=1 (queue active) > Aug 22 14:02:12 borg postfix/qmgr[1499]: B4693A377C: removed > Aug 22 14:02:12 borg postfix/smtp[2071]: 2EB94A371B: > to=<anne at borg.xxx.lan>, > relay=mailhost.zen.co.uk[212.23.3.98]:25, delay=0.75, > delays=0.04/0/0.16/0.54, > dsn=2.0.0, status=sent (250 OK id=1QvU8e-00085m-9o) > Aug 22 14:02:12 borg postfix/qmgr[1499]: 2EB94A371B: removed > Anne alternatives --config mta Switch to Postfix. Validate by alternatives --display mta then remove Sendmail if you do not use it. Alexander