Probably, we need to exclude the application using port 25 from
Access Protection Policies -> Settings for Server) -> Anti-Virus Standard Protection -> Prevent mass mailing worms from sending emails
Weather the "Access protection got disabled" or "Prevent mass mailing worms from sending" option got disabled ?
probably disabling "Prevent mass mailing worms from sending" will not disable the access protection
I disabled 'prevent mass mailing worms..' to unblock port 25 but I was incorrect about that disabling access protection. I recall seeing that happen in the past on some 8.5 & 8.0 VSE versions though even though I wouldn't think disabling '..mass mailing..' would turn off Access protection.