Symantec Messaging Gateway (SMG) configuration timeouts for SMTP transmissions may need to be changed.
Timeout occurs when defined value is reached in each phase as bellow:
---------------------------------------
1. When MTA doesn't exist or there is no return from the connect system call the bellow error message will be issued:
421 4.4.0 [internal] no MXs for this domain could be reached at this time
2. When there is no return from 220:
450 4.4.1 [internal] Connection Timed Out
3. When there is no return from EHLO :
450 4.4.1 [internal] Connection Timed Out
4. When there is no return from MAIL FROM:
450 4.4.1 [internal] Connection Timed Out
5. When there is no return from RCPT TO:
450 4.4.1 [internal] Connection Timed Out
6. When there is no return from DATA:
450 4.4.1 [internal] Connection Timed Out
7. When there is no return from RESET:
450 4.4.1 [internal] Connection Timed Out
The timeouts can be found in the Control Center under Administration > Host > Configuration > SMTP > Advanced settings > Delivery.
Connection Timeout : 30 seconds
EHLO/HELO Timeout : 5 minutes
MAIL FROM Timeout : 5 minutes
RCPT TO Timeout : 5 minutes
DATA Timeout : 10 minutes
RSET Timeout : 10 minutes
Idle Timeout : 5 seconds