ASG 7.504
Inbound email stopped suddenly just before 20:00 about two weeks ago. Email started queuing up at offsite mail backup service. No change had been made to the device configuration. SMTP proxy had been working fine for weeks.
Looking at packet filter log showed port 25 traffic was getting dropped. No firewall rule made to support that function.
Telnet to address from outside of Comcast network yielded no response. Comcast Business allows SMTP traffic port 25.
1. Created any-any-any rule. No success, 25 traffic continued getting dropped.
2. Removed rule.
3. Stopped SMTP Proxy.
4. Created DNAT rule for mail server. Telnet to 25 worked instantly.
5. Checked all settings, everything seems correct. Cannot account for why port 25 is being dropped when SMTP proxy running.
Any trouble shooting tips?
This thread was automatically locked due to age.
