C Panel Emails are not working behind the fortinet firewall Model:-300C

Please confirm that you have tested that all the appropriate ports from this list in opened/allowed

25, 110, 465, 587, 993, 2525, 2526

Also, the email host can be distributed on various actual hosts and if not all of them are allowed, you will get intermittent connection problems.

Dear Shaun Vermaak,

Thank for your Reply......

As you mention port, i have verify in my allow list and found that some port (2525,2526 and 587) is not in allow list, now i have put on allow list but still not working.
how to find out the email host can be distributed on various actual hosts.
pl. guide me on same.....and also i have attached the outlook error MSG.

Thanks
Ajay Panchal
Outlook-error-MSG.jpg

Dear Shaun Vermaak,

To overcome, inside the firewall network i'm able to ping my email server and also try to nslookup to my emails server that time also response was received.
if my laptop is out of firewall network at this time in outlook able to received mails and sending emails but i have connect my laptop inside the firewall network at this time is not working and i never understand what is the problem behind that issue.

Thanks
Ajay Panchal

Please telnet to 109.75.160.223 on the ports mention. Check if any of them don't work

Not able to telnet to host. below mentions error received while trying to telnet but 2 days back the mails are working smoothly inside the firewall network.

C:\>telnet 109.75.160.223
Connecting To 109.75.160.223...Could not open connection to the host, on port 23: Connect failed

C:\>telnet 109.75.160.223 110
Connecting To 109.75.160.223...Could not open connection to the host, on port 110: Connect failed

C:\>telnet 109.75.160.223 25
Connecting To 109.75.160.223...Could not open connection to the host, on port 25: Connect failed

C:\>telnet 109.75.160.223 465
Connecting To 109.75.160.223...Could not open connection to the host, on port 465: Connect failed

C:\>telnet 109.75.160.223 993
Connecting To 109.75.160.223...Could not open connection to the host, on port 993: Connect failed

C:\>telnet 109.75.160.223 587
Connecting To 109.75.160.223...Could not open connection to the host, on port 587: Connect failed

C:\>telnet 109.75.160.223 2525
Connecting To 109.75.160.223...Could not open connection to the host, on port 2525: Connect failed

C:\>telnet 109.75.160.223 2526
Connecting To 109.75.160.223...Could not open connection to the host, on port 2526: Connect failed

All of these 25, 110, 465, 993 work from my side, the rest are not used. You are definitely being blocked by a network or host-based firewall.
Can you export your Fortinet rules so that I can check?

in firewall i have create the one group as email access and add all service port as you mention and add one policy and sources is all (my lan network) and destination all and services is emails access as i have created and no any security profile was apply for this policy.

can we take a remote session with Teamviewer or Anydesk is it possible for you?

Dear Shaun Vermaak,

Pl. guide me on this problem.....

Hello Ajay,

If you are getting "Connect failed" error on telnet means traffic is blocked from your system itself. If it takes a while means connection is blocked on network level.

Can you sniff the traffic on FortiGate to see if the traffic is blocked by FortiGate or traffic itself is not reaching the FortiGate.
Sniff command: #diag sniffer packet any 'host your-system-ip and port 110' 4

Do telnet to server on port 110 Capture the sniffer output using putty and paste here.

Good Luck!