Unusual signals are the behavior or traits of an email that look suspicious to Trend Micro Email Security. A single unusual signal does not mean a definite threat but can indicate possible risks. When detecting one unusual signal in an email message, Trend Micro Email Security supports taking action on the message. For details about unusual signals, see Unusual Signals.
Trend Micro recommends that you use the "Do not intercept messages" and "Insert stamp in body" actions for unusual signal detection. A default stamp "Unusual signal detection" is available for use.


  1. Select Unusual signal.