Gnus email (or signature, or both) is seen as corrupted encoded file

[Gijs Hillenius]

I got a reply to an email this morning, and this (below) was part of
it. The quote marks were in the reply.

It suggests that the email I had sent was considered a virus. Most
likely a misconfiguration of the recipient's proprietary mail server,
perhaps triggered by my email signature?

Right?

,----
| > 
| > FILE QUARANTINED
| > 
| > Microsoft Forefront Protection for Exchange Server removed a file
| > since it was found to be infected.  File name: "Body of Message"
| > Malware name: "CorruptedCompressedUuencodeFile"
`----