Common Attachment Types Filter mis-identifying the contents of .zip files as .jar
The new Common Attachment Types Filter is a welcome addition to the anti-malware arsenal. The default configuration is supposed to block .jar files and allows .zip files. However, since they use the same encryption type, it misidentifies all .zip files as .jar files and blocks the message. Please add additional logic to distinguish between the two types, and allow .zip files that do not contain prohibited file types.
(I submitted this as a bug to support, but they said it's Working As Designed, and suggested posting it to Uservoice.)
Elliott G commented
I also got the same indifference from Microsoft and my vendor when I brought this up. This is a built-in feature with .jar added by default in the "Common Attachment Types" list, and it not only blocks all .zip files, it blocks .xlsx, and .docx files which are also .zip based files.
This is absolutely ridiculous, especially since if you only enable the filter it does not notify anyone by default that the e-mails are being blocked.