emails from server getting returned

[dlhill]

Hello,

I've have an email server that's running Slackware 11 and Sendmail 8.14.2 that was running fine until a few days ago. Users suddently started getting this message shortly after they send out email.

Subject: Warning: could not send message for past 4 hours.


**********************************************
** THIS IS A WARNING MESSAGE ONLY **
** YOU DO NOT NEED TO RESEND YOUR MESSAGE **
**********************************************

The original message was received at Mon, 11 Aug 2008 15:18:41 -0600
from mailserver.mydomainname.com [127.0.0.1]

----- Transcript of session follows -----
<userID@hotmail.com>... Deferred: Connection refused by mx3.hotmail.com.
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old

It also sends an attachment which contains the following.

Reporting-MTA: dns; mydomainname.com
Arrival-Date: Mon, 11 Aug 2008 15:18:41 -0600

Final-Recipient: RFC822; usrID@hotmail.com
Action: delayed
Status: 4.4.1
Remote-MTA: DNS; mx3.hotmail.com
Last-Attempt-Date: Mon, 11 Aug 2008 19:27:40 -0600
Will-Retry-Until: Sat, 16 Aug 2008 15:18:41 -0600

After the 5 days I get a Returned mail.

Subject: Returned mail: see transcript for details.

The original message was received at Fri, 8 Aug 2008 13:58:44 -0600
from server.mydomainname.com [127.0.0.1]

----- The following addresses had permanent fatal errors -----
<usrID@hotmail.com>

----- Transcript of session follows -----
<usrID@hotmail.com>... Deferred: Connection refused by mx3.hotmail.com.
Message could not be delivered for 5 days
Message will be deleted from queue

There is an attachment with this email as well that contains the following.

Reporting-MTA: dns; mydomainname.com
Arrival-Date: Fri, 8 Aug 2008 13:58:44 -0600

Final-Recipient: RFC822; usrID@hotmail.com
Action: failed
Status: 4.4.7
Remote-MTA: DNS; mx3.hotmail.com
Last-Attempt-Date: Wed, 13 Aug 2008 14:22:41 -0600

The line Reporting-MTA looked a little weird to me, so I did a telnet to our mail server and I got this

Telnet mailserver 25

220 mydomainname ESMTP Sendmail 8.14.2/8.14.2; Day Month Year time

To me, it looks like sendmail isn't pulling the server's name and attaching it to outgoing emails. Since the receiving email servers only get my domainname they think it's spam or something malicious and eventually bounce it back to us.

Believeing there's something in the sendmail.cf file that's configured wrong I did some checking and editing. So far, in the sendmail.cf file, I have edited the lines Fw and Dj like this.

Fw/etc/mail/local-host-names
Dj$m

The Fw line allows the server to recieve emails, and the Dj line gives our domainname since I'm not running DNS on this server. Two other servers are handling DNS and these two servers have been added to /etc/resolv.conf. I also added the mail server name to the /etc/mail/local-host-names.

Someone suggested that I find a line that starts with Cw and add myserver.mysomainname.com and then restart sendmail. I did but it didn't change anything.

Right now I'm drawing a blank. Which is why I'm posting. Hoping someone give me an idea or two. If you have a question or need more info, I'd be more and happy to give you what you need.

Thanx!

[HROAdmin26]

Did you change something in your config recently? If not, why do you think your config is the problem on something that's *been* working?

Connection refused by mx3.hotmail.com

Hotmail is refusing your connection. If you take the IP address of your mail server (that Hotmail sees) and do a reverse-lookup, do you get server.yourdomain.com or do you get something like 214-65-34-19.southeast.cable.rr.com?

It's not uncommon for large mail servers to deny mail delivery from home networks. You may need to bounce your mail thru your ISP's mail server.

[dlhill]

Thanks for responding to my post.

The reason I'm thinking it might be something in my sendmail.cf file is because when I look at the returned mail, the Reporting-MTA gives only my domainname rather than something like myserver.mydomainname.com. Also, when I telnet to my mail server I only get mydomainname.com when I should (I think) be getting myserver.mydomainname.com.

As far as changes to the .cf file, I've been changing the line that contain Dj and Cw to see if that would make a difference. Which it didn't.

From home I do a reverse lookup on our server and I get myserver.mydomainname.com.

Sorry for not mentioning this sooner but this isn't a home network but rather a network I maintain at a school.