Hello, i would create alias in my organisation to send "messages" for all emails (users). There is a option to block send attachments for this specific alias? Best regards.
No. You might be able to accomplish that with custom sieve mail filter(s), though not via the ISPConfig interface. If I were needing that ability, I'd probably look at having a simple web interface which accepts a subject/message and sender info, and formats/sends the message (with no attachment support), and not even have an alias that is mailable by the public.
