Attachment filter in ME has a bug.
When you specify which extensions to trigger this rule, ME does not look for extension, but actually for presence of this string, which is WRONG, for example:
You set to filter all attachments with extensions:
*.com
The filter trigers on:
file_name.com
filename.something.blahblah.com
which is OK
BUT it trigers also on:
filename.from.gmail.com.zip
picture121.downloaded.www.archive.com.gif
which is wrong!
I did workaround to this bug with logic, where I put Attachments filter to be the LAST one, and right before it there is a rule, which stops processing rules for messages over 500kB in size. With this order, most of user-friendly attachments pass thru, but it is NOT a good sollution.
So, please, fix this bug in further release.