There is an email on the server that stops 3 different clients from downloading it.
When I delete the email from the server all the legitimate emails download.
This email contains the following in the body and the url to the zip file is mastermatrix.com/bad/file.zip
I've never run across an email that would stop the client download and then not let anything else download

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I forwarded this message to my hotmail account and it says it is a virus and it is WORM_MYTOB.AO
there are references on trend micro
And I searched for any reference to it choking the email server
But could find nothing