Latest LQ Deal: Latest LQ Deals
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 03-07-2013, 03:12 PM   #1
Registered: Jul 2012
Posts: 37

Rep: Reputation: Disabled
dsn=5.7.1, stat=User unknown

I'm trying to configure sendmail on our Debian Linux server to send mail, using our Exchange server as a relay. I'm a total noob at all of this.

We can send mails to internal addresses (for example, if our domain name is, the server can send mail to with no problem.

We can't send mail to external addresses like or Here's an example of what I get in /var/log/mail.log

Mar 7 14:45:29 newton sm-mta[17159]: r27JjOw1017159: to=<>, ctladdr=<root@newton.forrest> (0/0), delay=00:00:05, xdelay=00:00:05, mailer=relay, pri=30455, [], dsn=5.7.1, stat=User unknown

Also, I get this:

root@newton:/etc/mail# sendmail -bv deliverable: mailer relay, host, user
Does that mean the is unknown to newton, or unknown to Exchange?

Is there something in Exchange we need to configure?

I have no idea what to configure. Please help. Thanks!
Old 03-08-2013, 09:34 AM   #2
Registered: Feb 2008
Distribution: Fedora,RHEL,Ubuntu
Posts: 661

Rep: Reputation: 66
Here error is from smtp , your exchange server communicating with gmail server and getting this response .

Old 03-08-2013, 10:15 AM   #3
Registered: Jul 2012
Posts: 37

Original Poster
Rep: Reputation: Disabled
Thanks for your reply.

I can send email to the "" address from any other computer and the message goes through. I've also tried sending to other external (yahoo, hotmail) addresses I have and they don't go through from our Linux server. I get the same error message ("User unknown") or "unable to relay".


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] Sendmail "user stat unknown error " while delivering error out sanjay87 Linux - Server 1 02-29-2012 10:54 AM
Sendmail dsn=4.0.0, stat=Deferred: Invalid argument error stephen_davies Linux - Software 1 07-03-2009 05:22 AM
Sendmail : relay=[] [], dsn=4.0.0, stat=Deferred: Connection refuse macadam Linux - Software 0 09-23-2007 03:44 PM
sendmail stat=User unknown problem mighlani Linux - Software 1 04-13-2006 10:32 AM
sendmail problem stat=User unknown singying304 Linux - Networking 1 10-07-2005 07:59 PM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 09:55 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration