In my experience, the vast majority of corporate mail filters ban certain file types based on name extensions.
Fewer, but some, inspect files to deduce their type.
None care about encrypted zips with the file renamed to a common extension (encrypted zip manifests are unencrypted, so the file names are still visible).
Fewer, but some, inspect files to deduce their type.
None care about encrypted zips with the file renamed to a common extension (encrypted zip manifests are unencrypted, so the file names are still visible).