Mail delivery failed... No Such User Here?!?

[klonos]

This mail server is working fine (sends & receives mail ok) other than the following issue with some domains:

-----Original Message-----
From: Mail Delivery System [mailto:Mailer-Daemon@Server.DomailMailWasSentFrom.net] 
Sent: Monday, November 17, 2008 1:03 PM
To: user@DomailMailWasSentFrom.net
Subject: Mail delivery failed: returning message to sender

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  user@DomailMailWasSentTo.net
    No Such User Here

------ This is a copy of the message, including all the headers. ------

Return-path: <user@DomailMailWasSentFrom.net>
Received: from static123045067890.ISP.DomailMailWasSentToUses.net ([123.45.67.890] helo=username)
    by Host.DomailMailWasSentFrom.net with esmtp (Exim 4.69)
    (envelope-from <user@DomailMailWasSentFrom.net>)
    id 1L21sl-0003VV-ML
    for user@DomailMailWasSentTo.net; Mon, 17 Nov 2008 05:03:14 -0600
From: =?iso-8859-7?B?yu/96uHyIMPp/vHj7/I=?= <user@DomailMailWasSentFrom.net>
To: <user@DomailMailWasSentTo.net>
Subject: test
Date: Mon, 17 Nov 2008 13:01:36 +0200
Message-ID: <0E5E1B6E9B65465BAED3E4FD6A3ABCC0@username>
MIME-Version: 1.0
Content-Type: multipart/related;
    boundary="----=_NextPart_000_0009_01C948B4.ABECB620"
X-Mailer: Microsoft Office Outlook 11
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579
Thread-Index: AclIoNYLeOPYb0M/SQe4/3g04l+lCQ==
X-ACL-Warn: {

This is a multi-part message in MIME format...

What could be wrong? How should I troubleshoot this further??

[falko]

Please check if that user is existing in your Postfix configuration. I'd check /etc/postfix/main.cf and all included files.

Also, check your mail log for errors.

[klonos]

Hey Falko,

The users are stored on a mysql db. And the user in question is in the db (actually, the issue is with all the users and they are all in the db).

Here is the main.cf file:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version

# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname - Welcome to DomainMailWasSentTo.net
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

# TLS parameters
smtpd_tls_cert_file = /etc/postfix/smtpd.cert
smtpd_tls_key_file = /etc/postfix/smtpd.key
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

myhostname = mail.DomainMailWasSentTo.net
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
#mydestination = mail.DomainMailWasSentTo.net, localhost, localhost.DomainMailWasSentTo.net
mydestination = mail.DomainMailWasSentTo.net, localhost, localhost.localdomain
relayhost = 
mynetworks = 127.0.0.0/8 10.0.0.0/24
#mynetworks = 127.0.0.0/8
mailbox_size_limit = 0
message_size_limit = 35840000
recipient_delimiter = +
inet_interfaces = all
virtual_alias_domains = 
virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-vforwardings.cf, mysql:/etc/postfix/mysql-vemail2email.cf
virtual_mailbox_domains = DomainMailWasSentTo.net
virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-vmailboxes.cf
virtual_mailbox_base = /home/vmail
virtual_uid_maps = static:5000
virtual_gid_maps = static:5000
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
transport_maps = proxy:mysql:/etc/postfix/mysql-vtransports.cf
virtual_create_maildirsize = yes
virtual_maildir_extended = yes
virtual_mailbox_limit_maps = proxy:mysql:/etc/postfix/mysql-vmailbox_limit_maps.cf
virtual_mailbox_limit_override = yes
virtual_maildir_limit_message = "The user you are trying to reach is over quota."
virtual_overquota_bounce = yes
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps
content_filter = amavis:[127.0.0.1]:10024
receive_override_options = no_address_mappings
readme_directory = /usr/share/doc/postfix
html_directory = /usr/share/doc/postfix/html

In the above text I have replaced the real domain with DomainMailWasSentTo.net (security reasons). Also, there are 3 things that differ from the main.cf in your HowTo:

1. filenames mysql-virtual*.cf have been replaced with mysql-v*.cf, but here is a listing of them under /etc/postfix:

ls -l mysql-v*
-rw-r----- 1 root postfix 140 2007-08-02 01:43 mysql-vdomains.cf
-rw-r----- 1 root postfix 125 2007-08-02 01:44 mysql-vemail2email.cf
-rw-r----- 1 root postfix 138 2007-08-02 01:43 mysql-vforwardings.cf
-rw-r----- 1 root postfix 194 2007-08-02 01:44 mysql-vmailboxes.cf
-rw-r----- 1 root postfix 125 2007-08-02 01:45 mysql-vmailbox_limit_maps.cf
-rw-r----- 1 root postfix 134 2007-08-02 01:45 mysql-vtransports.cf

I think I've been extra careful and haven't misspelled anything. Do the file rights seem ok to you?

Using the info I have in these files, I can successfully connect to the mysql server and the db that contains the user info:

mysql -u mail_admin -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8930
Server version: 5.0.67-0ubuntu6 (Ubuntu)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> use mail
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql>

2. I do not use a mysql-virtualdomain.cf file, but have a 'virtual_mailbox_domains = DomainMailWasSentTo.net' setting in the main.cf file, since this server serves only one domain.

3. I have added the local network (10.0.0.0/24) in the 'mynetworks =' setting, because I get the 'Relay access denied' error otherwise. (That is another issue I might resolve some other time)

Do you see anything I might be missing???

[klonos]

In the /var/log/mail.info log I see entries like:

Nov 19 07:54:03 mail postfix/smtp[15361]: D86431476AD: to=<user@DomainMailWasSentTo.net>, relay=127.0.0.1[127.0.0.1]:10024, delay=47, delays=37/0/0.01/9.9, dsn=2.5.0, status=sent (250 2.5.0 Ok, id=15351-01, DISCARD(bounce.suppressed))
Nov 19 07:54:03 mail postfix/qmgr[15340]: D86431476AD: removed

or:

Nov 19 07:37:45 mail amavis[13845]: (13845-19) Passed CLEAN, [some.IP] [another.IP] <someone@domain.net> -> <user@DomainMailWasSentTo.net>, Message-ID: <A0B82FC0DA3B44A0BF015E80A56C3AD8@useree29537c91>, mail_id: mR25E01XiPDS, Hits: -, size: 468027, queued_as: 5DE191476B0, 283 ms
Nov 19 07:37:45 mail postfix/smtp[15300]: D2C6B147693: to=<user@DomainMailWasSentTo.net>, relay=127.0.0.1[127.0.0.1]:10024, delay=2.6, delays=2.3/0/0/0.28, dsn=2.0.0, status=sent (250 2.0.0 Ok, id=13845-19, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 5DE191476B0)
Nov 19 07:37:45 mail postfix/qmgr[15340]: D2C6B147693: removed

for the certain user. This user receives mail from other domains. That means that there is no mysql db lookup issue. Right?

It is only from certain domains that when I try to send mail to this user I get the 'No such user here' error.

Also, I've googled it up and found that there might be a known issue with MS Outlook and Outlook Express that causes this issue. Both clients need the setting 'Server requires authentication' enabled to resolve this. Tried that with no luck.

Will try to tail the mail.info log when I send mail to this user from a domain that has this issue and let you people know.

In the meantime, any ideas are welcomed.

[klonos]

Also found out that these domains use exim 4.69. Don't know if that helps at all?!?

[falko]

What's the output of

netstat -tap

?

Do the users exist in the database?

[klonos]

netstat shows:

netstat -tap
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 localhost.localdo:10024 *:*                     LISTEN      7329/amavisd (maste
tcp        0      0 localhost.localdo:10025 *:*                     LISTEN      13138/master
tcp        0      0 localhost.localdo:mysql *:*                     LISTEN      4591/mysqld
tcp        0      0 localhost.localdo:spamd *:*                     LISTEN      4686/spamd.pid
tcp        0      0 *:www                   *:*                     LISTEN      4227/apache2
tcp        0      0 *:ftp                   *:*                     LISTEN      5441/pure-ftpd (SER
tcp        0      0 *:3128                  *:*                     LISTEN      5506/(squid)
tcp        0      0 *:2200                  *:*                     LISTEN      4502/sshd
tcp        0      0 *:smtp                  *:*                     LISTEN      13138/master
tcp        0      0 *:https                 *:*                     LISTEN      5565/apache-ssl
tcp        0      0 localhost.localdo:55683 localhost.localdo:mysql TIME_WAIT   -
tcp        0      0 localhost.localdo:mysql localhost.localdo:55651 TIME_WAIT   -
tcp        0     16 mail.DomainMailIsSentFrom.net:smtp     some.other.IP:24312 FIN_WAIT1   -
tcp        0      0 mail.DomainMailIsSentFrom.net:2200     IP.of.Their.ISP:3442 ESTABLISHED 5527/sshd: root@not
tcp        0    820 mail.DomainMailIsSentFrom.net:2200     IP.of.Their.ISP:2756 ESTABLISHED 22974/0
tcp6       0      0 [::]:imaps              [::]:*                  LISTEN      5773/couriertcpd
tcp6       0      0 [::]:pop3s              [::]:*                  LISTEN      5841/couriertcpd
tcp6       0      0 [::]:pop3               [::]:*                  LISTEN      5804/couriertcpd
tcp6       0      0 [::]:imap2              [::]:*                  LISTEN      5736/couriertcpd
tcp6       0      0 [::]:ftp                [::]:*                  LISTEN      5441/pure-ftpd (SER
tcp6       0      0 [::]:2200               [::]:*                  LISTEN      4502/sshd
tcp6       0      0 mail.DomainMailIsSentFrom.net:pop3     IP.of.Their.ISP:4685 TIME_WAIT   -

And yes, the users are in the db. They receive from and send mail to other domains just fine. Its just these about one dozen domains that give the 'No Such User Here' when they send mail to this server and to existing mail accounts.

[klonos]

I have Logwatch installed and among the daily reports I receive through mail is this:

sasl auth daemon Begin ------------------------ 

 
 SASL Authentications failed 19 Time(s)
 Service smtp (pam) - 19 Time(s):
    Realm  - 19 Time(s):
       User: inna - PAM auth error - 19 Time(s):
 
 
 **Unmatched Entries**
 
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 do_request      : NULL password received
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 pam_mysql - SELECT returned no result.
 
 ---------------------- sasl auth daemon End -------------------------

anything to do with our issue???

[falko]

Do the MX records of the not-working domains point to your server? You can check with

dig mx yourdomain.com

[klonos]

These domains are all hosted remotely and also share the same IP. I do not have access to remote shell on the server that hosts these domains, but will ask the sysadmins to run the command and mail me the output.

Will let you know as soon as I get an answer.

In the meantime this is what puzzles me:

I have setup 3 accounts:
myname@mydomain.net (my domain & my own account, everything been working fine for some years now)
admin@domain1.net (the server that I have set up about one year ago, works fine with all other domains, but not with domain2)
test@domain2.net (remote host with virtual domains (3rd party company), works fine with other domains, but not with domain1)

Troubleshooting Step1
Mail from mydomain.net reaches both domain1.net and domain2.net ok.
Mail from domain1.net reaches me ok (or gmail, or hotmail, or other domains as well).
Mail from domain2.net also reaches me ok (or gmail, or hotmail, or other domains).

Troubleshooting Step2
Mail from admin@domain1.net to test@domain2.net also cc'ed to myname@mydomain.net

Reaches myname@mydomain.net ok, but fails to reach domain2.net and returns:

This is the mail system at host mail.domain1.net.

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

<test@domain2.net>: host mail.domain2.net[IP.OF.domain2.net] said: 550-Verification
    failed for <admin@domain1.net> 550-No Such User Here 550 Sender verify failed
    (in reply to RCPT TO command)

What is this?? does the domain2.net server try to verify the sender by trying to send an email back before it receives the original mail sent to it? And if so, why does the domain1.net server reply 'No Such User Here'?

Troubleshooting Step3
And finally, mail from test@domain2.net sent to admin@domain1.net and also cc'ed to my account myname@mydomain.net received ok by both domains!?!.

See what I mean? If user admin@domain1.net is able to receive mail from test@domain2.net , then what is this 'Verification failed for <admin@domain1.net> 550-No Such User Here' error that the domain2 server spits and drives me crazy? What server gives this reply? Domain1 or domain2?