Spoofed messages often have mismatched message header senders (specified by the
header "From") and envelope senders (specified by the envelope field "MAIL FROM").
Trend Micro Email
Security provides an anti-spoofing check to
detect messages with a message header sender different from the envelope sender.
Procedure
- On the Scanning Criteria tab, click Advanced.
- Select Message header sender differs from envelope
sender.
Note
A message with a blank envelope sender does not match this criteria.