Greetings,



I used to manage a 32-bit Listserv 16 installation on a Red Hat Linux VM for many years, but I took a hiatus from that effort. Now, I am back managing the same Listserv server and I have a question.



Our Listserv server sometimes gets deluged with spam. The MTA on it is sendmail. We monitor the sendmail mqueue and get alerted via email and text message when it gets too high (above 600 messages). The mqueue on this server typically hovers around 300 messages, but lately, its been rising to 1,000 and remaining at that level for several days before it drops again.



As far as I can tell, much of it is spam where Listserv responds to it that its spam, but the responses typically are bounced. I am wondering what other Listserv sites do to reign in spam from being sent to Listserv. We have an Ironport device here, but we haven’t included Listserv in the list of servers it works with. Would that be a good option? My Ironport administrator has cautioned me against going in that direction due to a concern of too many false results.



Any suggestions will be appreciated.