SMTP Messages Stuck in Queue 1

[joelrob]

I upgraded a Windows 2000 server from Exchange Server 5.5 to Exchange Server 2000 three weeks ago. Everything was working fine until yesterday. I have 5 outside domains that all outbound mail to them is being held in the queue. All other outbound mail is being delivered fine. Only these 5 (so far) are getting stuck. 3 of the 5 have definitely received messages since the upgrade. I am receiving the following error in Event ID:

Source: MS ExchangeTransport
Event ID: 4000
Message delivery to the following domain 'CLIENT_DOMAIN.com' failed for the following reason: The connection was dropped by the remote host.

I have checked the databases to make certain we're not blacklisted, we are not an open relay and are not listed as such.

Our e-mail and webhosting are hosted by a third party, but our Exchange server sends all outbound mail directly, it does not go back to them. We have a T1 connection through, and previously had to configure mail to bounce off the ISP's server when we were running 5.5, but I assume this is not the problem as it was working fine until yesterday.

One odd thing is that I've noticed the queue will clear temporarily, all but one of the 5 will show as empty, but then they re-appear.

Any help is greatly appreciated.

 

[GlenJohnson]

Working on a similar problem. Can you ping the machines that you can't send mail to?

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin check out Tek-Tips in Chicago, Illinois Forum.

TTinChicago

http://www.johnsoncomputers.us

 

[joelrob]

Yes, I can ping them, I can even telnet in on port 25. I've done just about all the troubleshooting I can think of. I've read similar threads by others that said the problem went away after they re-installed IIS and Exchange. If I haven't resolved it by this weekend I'm going to try that.

 

[joelrob]

Well, I've broken down and paid the $245 for Microsoft to resolve the issue. After much troubleshooting they determined it was my T1 connection download. After telnetting in, all commands work until the Data command is issued, then it locks up. I have my T1 provider testing it now, but I don't believe this to be the problem. From my personal XP workstation I'm able to telnet in and successfully issue all commands, only from the server I'm not.

Will keep you up to date on any new developments.

 

[xmsre]

Well, let's examine what the differences and similarities are between telnetting to the server on port 25 from your workstation, and connecting to the same server from your exchange server.

1. Your workstation and the exchange server do not have the same IP addresses.
2. Telnet is running a single session of 1 connection, Exchange runs multiple sessions over 1 connection.
3. Mime encoding types.
4. Both are going over the same T1.


I thing if you tried telnetting to port 25 on the remote server from the console on your exchange server you may be able to narrow it down. If you can connect sucessfully this way, then I would assume the problem lies in 2 or 3 above. If you cannot, it's time to check your external DNS and check to see if your server is on any blacklists.

 

[joelrob]

Checking the blacklists was the first thing I did, Microsoft double checked as well.

Workstation and server will have the same IP address to the remote mail server, because our Exchange server has the only public IP address, all the rest are NAT.

Yes exchange would be running several sessions, but I wiped out all outgoing messages, had everyone disconnect then tried to send a single message to each of the domains, still no luck.

That leaves 3, what would I do to troubleshoot MIME?

 

[xmsre]

The MIME encoding of message body parts in IIS.

 

[joelrob]

OK, but how would that suddenly change? Monday afternoon I applied the latest security patches from Microsoft, shut down the server and re-started and that's when the problems started. Before that mail was being delivered fine, one of the domains that mail is not going through to is our biggest client, we mail back and forth many times a day.

 

[Greenback]

I had a similar problem.

In the end i just set up a connector for that particular domain and it works now - not ideal, but handy!

 

[joelrob]

Greenback,
I wouldn't mind doing that at all if it works. So far there's only 4 domains that are affected, so it wouldn't take that much. Do you have a link with instructions how to do so?

Thanks much.

 

[joelrob]

Actually I found a fantastic link for this located at:

http://www.msexchange.org/tutorials/Using_SMTP_Connector_Internally.html

I've tried it with one of the four and the messages all went.

 

[Greenback]

1) In ESM, drill down to Routing Groups

2) Go into First Routing Group, then Connectors

3) Right mouse click - New - SMTP Connector

4) Give it a name (natch)

5) Either allow DNS to resolve it, or if you have a smarthost, enter its name/ip

6) Add your bridgeheads if you want them

7) Then go to Address Space. Add an SMTP address space for the domain youre trying to send to IE companya.com. Set the cost if you use it.

Try that - works great for me!

 

[Greenback]

just as i typed it all out as well...

 

[joelrob]

I've set up the connector, it seems all the messages have gone for that one domain. They've done this to me before though, and then all pop back up a few minutes later. Will give it an hour or so and see if they come back. Either way will post again to let everyone know the results.

 

[joelrob]

This didn't work either, the messages do come back after 10 minutes or so. Am working through with Microsoft, appears there may be a problem with the security patch KB895372. These problems all started after a re-boot from applying this patch, so that may be it.

 

[ChristianJorgensen]

I am experiencing identical issues with my Exchange 2000 architecture. I uninstalled KB895372 and the problem has not been resolved. Did you find a suitable fix?

Thanks

 

[joelrob]

According to Microsoft, the only way to repair it will be to restore the server from a backup point before the patch was applied or do a clean install. I am opting for a clean install to address other minor issues as well. I am wiping the hard drive and re-installing. This server was only used for Exchange and Internet access, so all mailboxes are backed up nightly. It will be an inconvenience, but if this doesn't fix it nothing will.

 

[dewaynehasty]

I'm having the exact same problem! I can't get any email to go out to hotmail domain. All other domains seem fine. It all started after applying the most recent updates on Monday.

So far I can't figure it out

 

[moller]

I use IIS SMTP server in win2003 but I can't receive mails which sent in 7bit. how to solve it.


"Date: Thu, 6 May 2004 07:00:40 +0800"
"Content-Transfer-Encoding: 7bit

 

[1Swift1]

Mail gets stuck in Queue.

One possible solution is the configuration of your firewall. I run a network and the computers use Windows 2000 Pro & Office 2000 Premium, which has its own built-in SMTP service and the Internet Information Services. I dedicate one of the computers to relay all the email to the Internet, but I noticed email was being held in the Queue directory. I could manually move the files to the Pickup directory and they would immediately leave. After a little research I found that Norton Internet Security software was blocking the IIS with a default rule. Not only that, but if you use the Norton Parental Control feature, this will also prevent email from leaving the Queue.

Hope this helps for people with simular Firwalls.