I need to set up my Gateway running R80.20, so we can forward a copy of journald mails from MS365 to an Internal server running SMTP.
As all the mails are scanned on the outside I just want to do simple forwarding with just some threat prevention/IPS.
For this do I just enable the MTA on the Gateway and create a rule allowing the mail on port 25 to the Gateway ?
Will this have any impact to the load on the Gateway and cause any excessive cpu/memory usage, or will it be fine?
What benefits does this give me over doing a simple NAT to the mail server on the inside?