# SMTP Protocol Agent

On Firewalls, the Simple Mail Transfer Protocol (SMTP) Protocol Agent can be used to redirect connections to a proxy service. On Layer 2 Firewalls and IPS engines, the Protocol Agent can be used for protocol validation and deep inspection.

On Firewalls, this Protocol Agent has parameters that you can set in the Service properties. On IPS engines and Layer 2 Firewalls, there are no configurable parameters for this Protocol Agent.