maildrop : user unknown. Command output: Invalid user specified.

[mfrna]

first of all, I'm just a php developer but I have to manage servers as part of the job .. so please bear with my limited knowledge of unix commands/config

I have two dedicated servers to manage
both have been running fine for years

couple of days ago one of them started to show a weird problem with email

lets call them goodserver ,illserver

goodserver has many domains lets pick gsdomain1,gsdomain2 for example
illserver has two domains isdomain1 , isdomain2

illserver has the following weird behaviour

I send an email from me@gsdomain1 to anymail@isdomain1

the message doesn't make it and I get the following reply

This is the mail system at host localhost.gsdomain1

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<anymail@isdomain1>: user unknown. Command output: Invalid user
    specified.



Reporting-MTA: dns; localhost.gsdomain1
X-Postfix-Queue-ID: A1F653B0AE
X-Postfix-Sender: rfc822; me@gsdomain1
Arrival-Date: Tue, 18 May 2010 15:10:07 +0100 (BST)

Final-Recipient: rfc822; anymail@isdomain1
Original-Recipient: rfc822;anymail@isdomain1
Action: failed
Status: 5.1.1
Diagnostic-Code: x-unix; Invalid user specified.

however, goodserver sends/receives email fine to/from any other server
illserver sends/receives email fine to/from any other server
isdomain1 sends email to gsdomain1 fine
isdomain2 sends/receives email to/from gsdomain1 fine

so the problem is only when I send email from goodserver(gsdomain1/gsdomain2) to isdomain1

what can I do about that?

[Mark_NL]

tail -f /var/log/mail.log

on the ill server.

Then send another mail from GS to IS .. check check what appears in the mail.log

[mfrna]

Originally Posted by Mark_NL

tail -f /var/log/mail.log

on the ill server.

Then send another mail from GS to IS .. check check what appears in the mail.log

thanks Mark for your reply

Here's the output from first tail

May 19 15:51:34 localhost postfix/pipe[11425]: 657A34A592: to=<ayman@isdomain1>, relay=maildrop, delay=0, status=sent (isdomain1)
May 19 15:51:34 localhost postfix/pickup[11537]: 7AD0D4A64C: uid=1003 from=<smh>
May 19 15:51:34 localhost postfix/cleanup[11422]: 7AD0D4A64C: message-id=<201005191450.o4JEoWtR021877@media1.lon2.colo.j2noc.com>
May 19 15:51:34 localhost postfix/local[11556]: 6989A4A582: to=<smh@localhost.isdomain2>, relay=local, delay=0, status=bounced (cannot access mailbox /var/mail/smh for user smh. error writing message: File too large)
May 19 15:51:34 localhost postfix/qmgr[31910]: 7AD0D4A64C: from=<smh@localhost.isdomain2>, size=75509, nrcpt=1 (queue active)
May 19 15:51:34 localhost postfix/pipe[11548]: 657A34A592: to=<henry@isdomain1>, relay=maildrop, delay=0, status=sent (isdomain1)
May 19 15:51:34 localhost postfix/smtpd[11464]: disconnect from unknown[213.152.245.76]
May 19 15:51:36 localhost postfix/smtp[11559]: 7AD0D4A64C: to=<someone@gmail.com>, relay=gmail-smtp-in.l.google.com[209.85.135.27], delay=2, status=sent (250 2.0.0 OK 1274280696 w5si34234364mue.54)
May 19 15:51:36 localhost postfix/smtp[11277]: 657A34A592: to=<someoneelse@gmail.com>, orig_to=<uthra@isdomain1>, relay=gmail-smtp-in.l.google.com[209.85.135.27], delay=2, status=sent (250 2.0.0 OK 1274280696 u26si6972846mug.55)
May 19 15:51:37 localhost postfix/smtp[11274]: 875314A552: to=<tarredff1@slu.ru>, relay=mailx.hoster.ru[195.128.50.36], delay=259501, status=deferred (conversation with mailx.hoster.ru[195.128.50.36] timed out while sending HELO)
May 19 15:52:16 localhost pop3d: Connection, ip=[::ffff:188.221.171.76]
May 19 15:52:16 localhost pop3d: LOGIN, user=s.sandhu@isdomain1, ip=[::ffff:188.221.171.76]
May 19 15:52:16 localhost pop3d: LOGOUT, user=s.sandhu@isdomain1, ip=[::ffff:188.221.171.76], top=0, retr=0

sent an email then another tail

May 19 15:56:15 localhost postfix/cleanup[11748]: DBA7B4A64C: message-id=<20100519145615.DBA7B4A64C@localhost.isdomain2>
May 19 15:56:15 localhost postfix/qmgr[31910]: DBA7B4A64C: from=<>, size=5711, nrcpt=1 (queue active)
May 19 15:56:16 localhost postfix/pipe[11791]: 5F1EA4A60A: to=<fik.majdoub@isdomain1>, relay=maildrop, delay=3, status=bounced (user unknown. Command output: Invalid user specified. )
May 19 15:56:16 localhost postfix/cleanup[11745]: 3378E4A592: message-id=<20100519145616.3378E4A592@localhost.isdomain2>
May 19 15:56:16 localhost postfix/qmgr[31910]: 3378E4A592: from=<>, size=5287, nrcpt=1 (queue active)
May 19 15:56:16 localhost pop3d: LOGIN FAILED, ip=[::ffff:94.194.60.13]
May 19 15:56:16 localhost pop3d: Connection, ip=[::ffff:94.194.60.13]
May 19 15:56:18 localhost postfix/smtp[11806]: 127374A596: to=<tammara_zl@goldenware.com>, relay=mx1.goldenware.com[66.211.137.252], delay=8, status=sent (250 2.0.0 o4JEuF3F016245 Message accepted for delivery)
May 19 15:56:18 localhost postfix/smtpd[11760]: 4AB224A596: client=unknown[109.194.137.214]
May 19 15:56:18 localhost postfix/smtpd[11784]: disconnect from 58-27-154-165.wateen.net[58.27.154.165]
May 19 15:56:20 localhost postfix/cleanup[11748]: 4AB224A596: message-id=<2.2.32.201004191640250082d4a0@hoffler.com>
May 19 15:56:20 localhost postfix/qmgr[31910]: 4AB224A596: from=<vmerry_qs@hoffler.com>, size=1803, nrcpt=5 (queue active)
May 19 15:56:20 localhost postfix/pipe[11756]: 4AB224A596: to=<dgjyb@isdomain1>, relay=maildrop, delay=2, status=bounced (user unknown. Command output: Invalid user specified. )
May 19 15:56:20 localhost postfix/pickup[11537]: D2FD94A660: uid=1003 from=<smh>
May 19 15:56:20 localhost postfix/cleanup[11745]: D2FD94A660: message-id=<2.2.32.201004191640250082d4a0@hoffler.com>
May 19 15:56:20 localhost postfix/pipe[11834]: 4AB224A596: to=<henry@isdomain1>, orig_to=<troubleshooting@isdomain1>, relay=maildrop, delay=2, status=sent (isdomain1)
May 19 15:56:20 localhost postfix/qmgr[31910]: D2FD94A660: from=<smh@localhost.isdomain2>, size=1961, nrcpt=1 (queue active)
May 19 15:56:20 localhost pop3d: Connection, ip=[::ffff:196.219.226.26]
May 19 15:56:21 localhost pop3d: LOGIN, user=elana@isdomain1, ip=[::ffff:196.219.226.26]
May 19 15:56:21 localhost postfix/pipe[11832]: 4AB224A596: to=<haulkhoryrashid@isdomain1>, relay=maildrop, delay=2, status=bounced (user unknown. Command output: Invalid user specified. )
May 19 15:56:21 localhost postfix/smtp[11806]: D2FD94A660: to=<hamankwah@anotherdomain.com>, relay=gmail-smtp-in.l.google.com[209.85.135.27], delay=1, status=sent (250 2.0.0 OK 1274280981 y6si34251673mug.50)
May 19 15:56:21 localhost pop3d: LOGIN FAILED, ip=[::ffff:94.194.60.13]
May 19 15:56:21 localhost postfix/pipe[11818]: 4AB224A596: to=<ep@isdomain1>, relay=maildrop, delay=2, status=bounced (user unknown. Command output: Invalid user specified. )
May 19 15:56:21 localhost pop3d: Connection, ip=[::ffff:94.194.60.13]
May 19 15:56:21 localhost postfix/pipe[11796]: 4AB224A596: to=<hooting@isdomain1>, relay=maildrop, delay=2, status=bounced (user unknown. Command output: Invalid user specified. )
May 19 15:56:21 localhost postfix/cleanup[11748]: F34A74A60A: message-id=<20100519145621.F34A74A60A@localhost.isdomain2>
May 19 15:56:22 localhost postfix/qmgr[31910]: F34A74A60A: from=<>, size=4350, nrcpt=1 (queue active)
May 19 15:56:22 localhost pop3d: LOGOUT, user=elana@isdomain1, ip=[::ffff:196.219.226.26], top=0, retr=0
May 19 15:56:22 localhost postfix/smtp[11806]: F34A74A60A: to=<vmerry_qs@hoffler.com>, relay=mx.netidentity.com.cust.hostedemail.com[216.40.42.4], delay=1, status=bounced (host mx.netidentity.com.cust.hostedemail.com[216.40.42.4] said: 554 5.7.1 <vmerry_rerwrqs@hoffler.com>: Recipient address rejected: user vmrewrwerry_qs@hoffler.com does not exist (in reply to RCPT TO command))
May 19 15:56:24 localhost postfix/smtp[11749]: DBA7B4A64C: to=<shellywerewrtheresiauf@uhc.com>, relay=mail10.cerworpmailsvcs.com[1.203.174.9], delay=9, status=sent (250 ok:  Message 573474153 accepted)
May 19 15:56:27 localhost pop3d: LOGIN FAILED, ip=[::ffff:94.194.60.13]

[Mark_NL]

Ehm, that server looks likes it's an open relay server :/

it's accepting mail from all kinds of clients towards all kinds of receipients!

"Command output: Invalid user specified", have you specified any catch all addresses? does user "ayman" exists? etc ?

[mfrna]

actually, it seems like it does

as for users, I'm sure that most of the users that I specify do exist

as I said .. I'm sending from me@gsdomain1 to me@isdomain1