Email Delayed for One Domain

[MJNSBF]

I have a user that is replying to an email outside the organization, and it is getting delayed and eventually undeliverable. I see it sitting in the queues with a 'retry' status. All other messages are going through fine. My first thought is that it's something on the other end, but is there something I can check on my side to ensure it isn't me. I'm currently playing "it's not my server" with the other group. Thanks in advance.

 

[noveyron]

What does the undeliverable say?

 

[MJNSBF]

Your message did not reach some or all of the intended recipients.

Subject: RE: Project
Sent: 5/5/2008 4:15 PM

The following recipient(s) cannot be reached:

John Doe on 5/6/2008 4:34 PM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
<x.x.x.x #4.4.7>

 

[noveyron]

The first place I would look is whether you have a rDNS record or not

http://postmaster.aol.com/tools/rdns.html

If that is ok, what happens when you telnet 25 to their mailserver?

 

[2624a]

Can the affected user send email to another user internally.

 

[MJNSBF]

Yes, we do have a rDNS record. The affected user can send email to both local and non-local recipients. It is only this one external domain that she can't get email to. I'm not real familiar with the telnet commands. But I will look that up and see what I can find out.

 

[noveyron]

telnet :

http://support.microsoft.com/kb/153119/en-us

 

[MJNSBF]

Thanks for the telnet info. Everything appears fine when I telnet into that server. No errors reflected through the telnet session. Although I had to be a fast typer or the connection would get lost. I was able to telnet and enter commands at my leisure to my server.

 

[MJNSBF]

The email was tried again this morning and it is still in 'retry' mode. Interesting tho, I have one more queue that is in 'rety' mode that has been sitting there for about an hour. I know this user successfully sent email to that domain before. Nothing has changed on our server, so I'm kind of at a loss at what else to look at.

 

[noveyron]

Another thing to eliminate apart from rDNS is to check whether you are on any spam blacklists. Here is a link for spamhaus, you may want to try some others too

http://www.spamhaus.org/lookup.lasso

 

[MJNSBF]

I went to mxtoolbox.com and did the blacklist test on their site. It said I was ok on them. What about graylisting? Could a company have our domain graylisted? Is that used very much?

 

[noveyron]

Yep, they could have done, there is a workaround here

http://technet.microsoft.com/en-us/library/aa998772.aspx

which involves adjusting the glitch retry interval.

Alternatively, is using a smarthost an option for you in this case?

 

[58sniper]

If you're greylisted, it would eventually go through on the retry. Greylisting only stops those servers that don't retry.

Are you publishing SPF records that could be incorrect?

Pat Richard
Microsoft Exchange MVP
Contributing author The Complete Reference: Microsoft Exchange Server 2007

 

[MJNSBF]

Ok, i performed the workaround and asked the senders to retry again. It goes immediately to retry state. At this point, using a smarthost is not an option. We do not have any spf records published.

 

[58sniper]

Is this maybe a DNS lookup issue? From that server, doing an NSLOOKUP, can you get the MX record for the destination domain?

Pat Richard
Microsoft Exchange MVP
Contributing author The Complete Reference: Microsoft Exchange Server 2007

 

[MJNSBF]

did an NSLOOKUP and got the MX record for the destination domain. this is just bizarre to me. Thanks for all the help so far!

 

[noveyron]

Long shot based on Pat's Spf incorrect comment, I dont suppose your rDNS is pointing at your router address instead of your exchange? Like I said, a long shot.

The telnet problems may benefit from a bit of googling as well?

nv

 

[MJNSBF]

long shots welcome at this point! But no, the rDNS is pointed at my exchange. I tried the telnet again earlier and was able to send a message to that recipient. They notified me that they received it. The message is just hanging in 'retry' mode on exchange.

 

[MJNSBF]

Things have been working great for awhile. No changes to the server at all. Just started happening for this one particular domain...but now I am seeing it for one or two other domains throughout the day, until the message expires. Not sure what could cause this...surely not related to database size or anything like that is it? (going for a long shot here myself)