LITTLEBLACKDOG.COM

Hi everyone. I'm turning to LWD for help.... I have a problem I've been dealing with for a while. I've read almost everything I can find on this site and others, but none are working so far.

I have an Exchange 2000 server running on Win2k. Users quite often get 4.4.7 messages when trying to email "some" domains. It doesn't happen to all domains.

I have checked DNS, Reverse DNS and all is ok. I am able to Telnet into port 25 of one of the suspected domains and am able to send mail fine using the Mail From:, RCPT To: etc.

I can replicate the issue, by logging into the server, launch outlook, add an attachment and send away. The attachment I'm using is 202k and it's a PDF - nothing major. The mail sits in the SMTP virtual server queue. If I send the same email without the attachment - it goes through. If I stop and start the queue... the mail still sits there.

Application event log shows a lot of 9302 warnings, but MS says not to worry in Exchange 2000.

Once in a while I get a DCOM error in the event log of 10009 saying it can't connect to the domain I'm sending to: mail.DomainMaskedforPrivacy.com.

SMTP diag shows no issues, but again - that's just doing a telnet and there's no attachment.

I'm using a PIX with one to one NAT, T1 through Verizon... ummm... anything else I'm missing to help YOU - let me know.

I've read a few things that say header limit on the firewall on the receiving end may cause this, but I'm an IT consultant and have many other clients with the same setup with no issues.

Any thoughts would be wonderful. It's driving me nuts.

Thanks.

Posted: Mon Dec 31, 2007 3:03 pm Post subject:

it could be something as simple as the "remote" address refuses attachments

Posted: Mon Dec 31, 2007 6:30 pm Post subject:

When the error occurs, how many recipients is the e-mail going to? (Header issue).

Are you using a smarthost to send the mail? If not, can you use one to test and see if this resolves the issue (Would point back to a DNS issue).

Just because an e-mail goes through without an attachment wouldnt rule out a DNS issue. Any filter's they use may use this as a flag to perform some sort of DNS Lookup which may be failing.

Posted: Tue Jan 01, 2008 7:34 am Post subject:

fathertyme wrote:
it could be something as simple as the "remote" address refuses attachments

I've been able to get the same error sending to my company which does accept attachments.

Posted: Tue Jan 01, 2008 7:38 am Post subject:

Extreme wrote:
When the error occurs, how many recipients is the e-mail going to? (Header issue).

Are you using a smarthost to send the mail? If not, can you use one to test and see if this resolves the issue (Would point back to a DNS issue).

Just because an e-mail goes through without an attachment wouldnt rule out a DNS issue. Any filter's they use may use this as a flag to perform some sort of DNS Lookup which may be failing.

It happens with even one recipient. I've thought about the header issue as I read that somewhere - and the article I read was talking about Sonicwalls specifically. One of the trouble domains is using a sonicwall. But I'm not sure where to control that in Exchange 2000.

No smarthost setup. Would I have to call Verizon and have them allow it?

Posted: Tue Jan 01, 2008 8:29 pm Post subject:

Spot wrote:

It happens with even one recipient. I've thought about the header issue as I read that somewhere - and the article I read was talking about Sonicwalls specifically. One of the trouble domains is using a sonicwall. But I'm not sure where to control that in Exchange 2000.

Found the following which may fit the bill at http://support.microsoft.com/kb/944280

Quote:

CAUSE
These issues occur if any one of the following conditions is true:
• You are running SonicWALL firewall from Sonic Systems Inc. These issues may occur if the port to which this firewall is connected is not set to 10 megabytes (MB) half duplex.
• You enable the Simple Mail Transfer Protocol (SMTP) Proxy service on the WatchGuard Firebox. If you use the SMTP Proxy service to specify which message headers are included with a message, the SMTP Proxy service may remove the bdata (binarymime) packet from the message transmission. This behavior may cause an NDR.

Back to the top
WORKAROUND
To work around these issues, use one of the following workarounds, depending on which firewall you are using.
If you are running SonicWALL firewall
Configure the port on the router on which the SonicWALL firewall is connected. Configure this port to 10 MB half duplex. For more information about how to do this, contact the manufacturer of the router.

For information about how to contact about how to contact the manufacturer of the router, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base:
65416 (http://support.microsoft.com/kb/65416/) Hardware and software vendor contact information, A-K

60781 (http://support.microsoft.com/kb/60781/) Hardware and software vendor contact information, L-P

60782 (http://support.microsoft.com/kb/60782/) Hardware and software vendor contact information, Q-Z
If you use the SMTP Proxy service on the WatchGuard Firebox to specify which message headers are included with a message
To work around this issue, disable the WatchGuard Firebox SMTP Proxy service. WatchGuard has a software update to correct this behavior. To obtain the update, contact WatchGuard support.

Spot wrote:

No smarthost setup. Would I have to call Verizon and have them allow it?

I'm assuming that Verizon is not blocking access to other SMTP servers running on port 25, so technically you can use any other known working SMTP Server.

If you have no other servers available, then you can try to use Verizon's SMTP Server that is used by other users on their network without authentication. If mail is not sent, then you may need to enable authentication and use a Verizon e-mail account/password. This is only if the above doesn't work out...