using Sender Verification Exception I can block user@example.com, user@, @example.com, @.example.com, @[1.2.3.4])
using Mail Policy I can block user@example.com, user@, @example.com, @.example.com
I could use content filters or message filters with condition:
mail-from == "@\\[?[0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+\\]?$"
and drop() action,
in Mail Flow Policy I have Envelope Sender DNS Verification = "On" - it does not have any impact
Where can I have some regular expression @\[?[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\]?$ to reject the sender?
OR
Which setting would reject such senders?
(I would prefer to reject, not silent-drop)
