I’m trying to move Office 365 connector authentication from IP-address to certificate. A Let’s Encrypt certificate has been created (on SFOS 21) and added to the SMTP TLS configuration under the Email > General tab. When changing the Office 365 connector to certificate, outgoing email on the XG are bounced with the error message “550 5.7.64 TennantAttribution; Relay Access Denied [ValidationStatus of “ is EmptyCertificate]”. According to Office 365 support articles this is due to “The certificate was null or empty during the chain validation process”. I assume this means SFOS is not using the chosen certificate on outbound communication.
Is it possible to use certificate authentication when using XG MTA for outbound SMTP?
Added V21
[edited by: Erick Jan at 4:36 AM (GMT -8) on 12 Nov 2024]