delayed delivery to specific domain - only when email has attachment

[NotThatTechie]

Here's a strange one...
We are having an issue where emails with an attachment are not getting delivered in a timely manner to a specific domain. Mail without attachments gets there in less than a minute however, when an attachment is there, it takes about 10 minutes or more to get through to their server (per message tracking in Exchange 2003 server).

-We have turned off our Symantec AV completely.
-We do not block attachments
-I don't believe it's DNS related since the other emails get to them as expected.

The company we are sending to uses a consultant who hosts their mail for them. He said they have turned off their AV product as well and has confirmed we are on their whitelist.

Any clues on what might cause a delay in mail (only when sending attachments)?

 

[Marcs41]

Since it is obviously on their end, there is not much you can do...

Marc
_{If 'something' 'somewhere' gives 'some' error, expect random guesses or no replies at all.
Free Tip: The F1 Key does NOT destroy your PC!}

 

[NotThatTechie]

i wish that was good enough to tell my customer. The consultant seems to think he has a flawless system and doesn't think it's on his end. He is arrogant and uncooperative. I'm just trying to find a solution for our customer with whom we can't communicate any time we have attachments.

Does anyone know what else i could possible look at to give me a clue why emails with attachments would be delayed.

 

[Marcs41]

The whole point is, when the flaw is not on your side, what do you expect to find?
There is nothing, absolutely nothing you can check or do.
If the 'other' admin thinks he is right, that is his problem.
I know some too that are 'arrogant' enough to claim any flaw cannot be on theit side, but if they are the only ones not receiving attachments ... how much more evidence do they need huh?

Are the having troubles with others too?
Try sending an attachment from Hotmail or so, to see if that gets there.

Marc
_{If 'something' 'somewhere' gives 'some' error, expect random guesses or no replies at all.
Free Tip: The F1 Key does NOT destroy your PC!}