Hi guys!

Due to information leaking from my company, i need to prevent sending
certain file types from inside to outside. However, sending attachments
of those types shoild be allowed from inside users to inside users, and
from outside to inside.

Is there a posibility to do this with postfix restriction rules?

I do filter messages by file type using header_checks regexp, but this
aplies to ALL attachments, so i cannot use this feature to solve my
issue.

I appreciate your time!

Best wishes,