On Weekend i installed 8.5.2 IF2.
After Upgrade we had Problems with incoming emails with attachments.
The Base64 Decoding did non run on these Attachments!
When Decoding with a tool like http://4mhz.de/ i was able to decode.
Subject: me too
we had the same issue after installing this fix. It solved the problem wit a loop in nsmtp when retrieving a smtp message but it had this poor side effect.