GWIA SMTP send threads hanging on NetWare with GroupWise 7.0.3HP

Since upgrading to GroupWise 7.0.3hp Some files are very slow to leave the send folder on the GWIA gateway. This ties up all available send threads causing long delays in processing out bound Internet mail.

In examining the GWIA logs it was discovered that the messages would process to the point where a connection is established with the receiving host but then nothing happens for up to an hour or so. Eventually the message processes or there is a 420 TCP read error and the messages is sent through the defer process. The messages were then transferred without problem.

Assuming the delay was on the receiving end of the transaction, the GWIA logs were searched for other traffic bound for the same domains. In some cases(yahoo.com) there were several examples of successful transactions before, during and after the message that was delayed. In other cases less popular domains had very limited traffic. There seemed to be no pattern to which destination domains were involved in the delays.

The number of SMTP send thread were increased to 32 in this case.  This allowed for the 10 - 20 commonly delayed threads to remain active and still allow for enough threads to process the active mail.

The problem has been reported to development as well to determine why the inactive threads do not time out or fail in a more timely fashion.