This article applies to all MetaDefender Email Gateway Security instances deployed on Windows operating systems (on-premise).
OPSWAT Email Gateway Security (EGS) On-Prem supports mutual TLS (mTLS) for outbound SMTP connections. This allows the EGS server to authenticate with a remote SMTP server using a client certificate during the TLS handshake.
First, the certificate needs to be added under Settings > Certificates:
Then this certificate can be used for the outbound SMTP connection under Settings > Server profiles:
However, mTLS is not supported for inbound SMTP connections. The inbound SMTP server in EGS does not perform client certificate verification, so mutual TLS cannot be enforced for incoming SMTP sessions.
If you have any questions, concerns or issues regarding MetaDefender NetWall products, please open a Support Case with the OPSWAT team via phone, online chat or form, or feel free to ask the community on our OPSWAT Expert Forum.
