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I recently set up my server using Centos 6, with ISPconfig 3 with httpd, php, mysql, mail server. I can create e-mail accounts in the control panel, And I successfully can log in to the webmail, I tried to send a message to my other e-mail on a other provider, And I received it, And tried to send a E-Mail to my server ( , and The mail server responds, But refuses it with this back.

From:  (Add as Preferred Sender)    
Date:   Tue, Jan 29, 2013 11:11 pm
This is the mail system at host

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

<>: unknown user: "tek"

Attached Delivery report

Reporting-MTA: dns;
X-Postfix-Queue-ID: CD9571A1312
X-Postfix-Sender: rfc822;
Arrival-Date: Wed, 30 Jan 2013 00:11:00 +0100 (CET)

Final-Recipient: rfc822;
Original-Recipient: rfc822;
Action: failed
Status: 5.1.1
Diagnostic-Code: X-Postfix; unknown user: "tek"

I set everything up with help from this guide, No problems with the install, But somehow, The mail doesn't deliver to the account/s.


#  Aliases in this file will NOT be expanded in the header from
#  Mail, but WILL be visible over networks or from /bin/mail.
#       >>>>>>>>>>      The program "newaliases" must be run after
#       >> NOTE >>      this file is updated for any changes to
#       >>>>>>>>>>      show through to sendmail.

# Basic system aliases -- these MUST be present.
mailer-daemon:  postmaster
postmaster:     root
mailman:              "|/usr/lib/mailman/mail/mailman post mailman"
mailman-admin:        "|/usr/lib/mailman/mail/mailman admin mailman"
mailman-bounces:      "|/usr/lib/mailman/mail/mailman bounces mailman"
mailman-confirm:      "|/usr/lib/mailman/mail/mailman confirm mailman"
mailman-join:         "|/usr/lib/mailman/mail/mailman join mailman"
mailman-leave:        "|/usr/lib/mailman/mail/mailman leave mailman"
mailman-owner:        "|/usr/lib/mailman/mail/mailman owner mailman"
mailman-request:      "|/usr/lib/mailman/mail/mailman request mailman"
mailman-subscribe:    "|/usr/lib/mailman/mail/mailman subscribe mailman"
mailman-unsubscribe:  "|/usr/lib/mailman/mail/mailman unsubscribe mailman"
# General redirections for pseudo accounts.
bin:            root
daemon:         root
adm:            root
lp:             root
sync:           root
shutdown:       root
halt:           root
mail:           root
news:           root
uucp:           root
operator:       root
games:          root
gopher:         root
ftp:            root
nobody:         root
radiusd:        root
nut:            root
dbus:           root
vcsa:           root
canna:          root
wnn:            root
rpm:            root
nscd:           root
pcap:           root
apache:         root
webalizer:      root
dovecot:        root
fax:            root
quagga:         root
radvd:          root
pvm:            root
amanda:         root
privoxy:        root
ident:          root
named:          root
xfs:            root
gdm:            root
mailnull:       root

Tried to make a e-mail account named and Did not get any errors, But didn't receive it in the inbox, But in the /var/spool/mail/root.

From ***********  Thu Jan 31 01:01:52 2013
Return-Path: <*********>
Received: from localhost (unknown [])
        by (Postfix) with ESMTP id 083BF1A131E
        for <>; Thu, 31 Jan 2013 00:01:52 +0000 (UTC)
X-Virus-Scanned: amavisd-new at
Received: from ([])
        by localhost ( []) (amavisd-new, port 10024)
        with ESMTP id 2XRR49L51PYm for <>;
        Thu, 31 Jan 2013 01:01:51 +0100 (CET)
Received: from ( [])
        by (Postfix) with ESMTPS id B6C001A1314
        for <>; Thu, 31 Jan 2013 01:01:50 +0100 (CET)
Received: by with SMTP id fo13so1371099vcb.25
        for <>; Wed, 30 Jan 2013 16:01:34 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113;
MIME-Version: 1.0
X-Received: by with SMTP id v18mr5586245vde.79.1359590494567;
 Wed, 30 Jan 2013 16:01:34 -0800 (PST)
Received: by with HTTP; Wed, 30 Jan 2013 16:01:34 -0800 (PST)
Date: Thu, 31 Jan 2013 01:01:34 +0100
Message-ID: <>
Subject: Grr
From: Andreas Teknikk <**********>
Content-Type: multipart/alternative; boundary=20cf307ca38e77fe3004d48a540b

Content-Type: text/plain; charset=ISO-8859-1

Why doesn't the other accounts work?



Was trying around things in the control panel, And added my other domain to the e-mail [Domains] in ISPConfig, And created a test account

And tried to send a test mail to it using GMail, and suddently, It arrived, And then i tried my main domain, And then i got the Error User not exist, When it does exist.

So what I am wondering, Is it because the server hostname is my main domain, Cause I tried a different domain I had, and It worked with no problems ._.

I tried to delete the main domain from the cpanel, And readded it, And still didn't work.

So, If i use my main domain, The e-mails won't arrive, But If I use my second domain, It arrives.

I'm confused, Cause, Why does a other domain work, And not the main domain?

Cause I need to get it fixed, As I use my main domain for things.

Issue fixed

This problem is now fixed, Had to change the mydestination that postconf | grep ^mydestination Showed to a other, changed it to, and after that, I received the test mail's i sendt.

share|improve this question

closed as off-topic by HopelessN00b Mar 8 '15 at 20:23

  • This question does not appear to be about server, networking, or related infrastructure administration within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

Silly question i know, but does the user tek exist? Diagnostic-Code: X-Postfix; unknown user: "tek" – Steve Jan 29 '13 at 23:28
@Mike [root@teknikk security]# netstat -tlupn | grep 25 tcp 0 0* LISTEN 1917/master tcp 0 0* LISTEN 1917/master tcp 0 0 :::25 :::* LISTEN 1917/master – Teknikk Jan 29 '13 at 23:37
@Steve The CPanel is showing that The user I created does exist. – Teknikk Jan 29 '13 at 23:39
@Teknikk, can you do a more on /etc/aliases – Steve Jan 29 '13 at 23:53
Im wondering if although ISPConfig thinks it has created the user, it hasnt actually been loaded into the postfix config.. im afraid i dont know enough about ISPconfig to comment. But the error Diagnostic-Code: X-Postfix; unknown user: "tek" really points to the postfix service not knowing about the user. – Steve Jan 30 '13 at 10:13
up vote 1 down vote accepted

Is postfix configured to accept mail for the domain?

postconf | grep ^mydestination ?

I know it doesn't sound right because of the unknown user error, but it's worth checking.

share|improve this answer
Well, It says that my domain is in it. [root@teknikk web]# postconf | grep ^mydestination mydestination =, localhost, localhost.localdomain – Teknikk Jan 31 '13 at 1:15

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