Each SMTP protocol exchange has a time-out wait value. If the client does not respond within the time-out period, the connection is broken.
Unfortunately it would appear that the connection is NOT being broken in our environment and the Internet/SMTP mail begins to queue in the mail.box
Bouncing the SMTP task seems to refresh the connection, but this is not a longterm solution.
I think the issue may lie in the way we are referencing our SMTP relay server. It is simply listed as SMTP.COMPANYNAME.NET however that is simply a DNS entry for two SMTP Relays.
SMTPOUT1.COMPANYNAME.NET and SMTPOUT2.COMPANYNAME.NET
The established connection is being made to SMTPOUT1, but if that server fails, then Domino is not failing over to SMTPOUT2.
Is this by design, would it be better to reference the two SMTP servers directly in connection documents?
The SMTPTimeoutMultiplier is irrelvant here I believe but maybe this is releveant
SMTP_Config_Update_Interval
Thoughts?