I have gotten 57 of these today and don't know what it is. None of my colleagues get it. And it shows up on my storm and in my ms outlook.

"This message is used to carry data between the BlackBerry handheld and an associated server. Please do not delete, move or respond to this message - it will be processed by the server.

BEGINETP 115
AQZ5n0gAAAAAIBAIMzA2NUFDRjMgGFJsZWVAc2FnaW5hd3Rvd2 5zaGlwLm5ldACONTDtUAVD
TUlNRQNAgICAgDIAADAzNjIzNTBFMStHKzIAm+V+vpcqfPROsY z7BCMMNQAZAwqnPNa2R5oa
YkK1pRnSLQ!!
ENDETP 890408687"

Looks like you installed BlackBerry Desktop and chose the BlackBerry Redirector option.
Probably shouldn't have done that.

Doesn't that also come from enterprise activation (BES server)?

Yes it does, but only once. If you're getting multiple emails like that, then what penguin said is true.

Here's how to fix it:

I keep getting odd emails from RIM - BlackBerryFAQ