Problem receiving from certain individuals

[Creeker]

We are having difficulty receiving mail from only certain individuals, 2 or 3 that we know of. Our mail comes in to a company that handles our domain. They point the mx record to our MS Exchange server that is set to receive all mail addressed to our domain with no size limits set.

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Subject: Undeliverable Mail

The message these people get is "Delivery failed 20 attempts:"
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I do not see any reference to it being rejected by any server.

I've been told by the people managing our domain that it has to be our Exchange server that is "too busy". Funny that every other piece of mail comes in fine including tons of junk mail. There are only 4 PCs in the network. What would make mail from just a couple individuals fail to get in. The emails in question were not large, no attachments, just text.

Can anyone give me an idea of where the problem might be?

 

[russeder]

Did you say that you got the MX records changed, I got this done lately and had the same issue as your self. If this is the case then it will take up to 48 hours for the whole world to get that new change and that would be the reason that you are only getting mails from some people.

 

[Creeker]

No, the MX record has not changed. It's been the same for a long time. The only change/trouble lately is that the server hosting our domain was hit with a virus and it screwed up all email for a few days. This has supposedly be fixed. That was about a month ago and they say all is well with their server.

 

[Creeker]

Just an update on the resolution to this problem.

After much discussion with technical support people with no resolution, an outside advisor told me the company that handles our domain needed to rebuild our MX record. (They had had a virus and had to rebuild their servers but still denied that it was their problem.)

Eventually our technical support people told them to create an "A" record for our email domain. Low and behold, it worked.