Section 5 Advanced SMTP Topics
This section discusses several diverse topics at the SMTP mail server level that can affect LISTSERV's operations.
Section 5.1, SMTPL-level spam control for Windows, explains how to integrate spam filtering at the SMTPL.EXE "listener" level so that spam can be identified and rejected prior to reaching LISTSERV. Since SMTPL is multi-threaded, this can significantly increase single-threaded LISTSERV's throughput efficiency by the simple expedient of stopping spam before it ever gets to LISTSERV's inbound spool.
Section 5.2, SMTP Worker Pool support, allows a large LISTSERV site to run large lists on a server and also (with appropriate hardware) to set up high-speed, low-volume delivery nodes for command responses and the like.