Hi Steve, On 02:05 PM 3/12/2002 or thereabouts, you wrote: >What alternatives are there for an SMTP service colocated on the Listserv >box? I seem to recall a new one recently being announced. First the good news. I have Post.Office (3.5.3) and eventually got it to work with Listserv Lite 1.8d. You need 2 MX records, one for mail.yourdomain.net and another for listserv.yourdomain.net, both resolving to the same IP. Edit your site.cfg file, add the line SMTP_LISTENER_PORT=1234 (for example) Create an entry in Post.Office's SMTP routing table to route all messages from listserv.yourdomain.net to mail.yourdomain.net#1234 (continuing the example). Restart the Listserv and SMTP listener services (running Win2K Advanced Server here). Send a "thank you" message to [log in to unmask] Getting that first "You're welcome!" reply was most gratifying. Then the bad news. Test replies started to queue up on the Post.Office server, rejected by several large sites like attbi.com and yahoo.com. Turns out that the outbound Listserv messages are relayed (even though you might think they're local) and have null (<>) User-From and Reply-Tos in the envelope and header. This is in compliance with RFCs 822 & 1123, but these big sites appear to be rejecting such messages since they "might be spam". Plan B. I installed LSMTP Lite evaluation version and it worked like a charm. This free version appends an [ Eval blurb ] in the subject line of every outbound message and 6 lines of Comments: in some classes of messages. For $500 and $100 per year maintenance (for LSMTP Lite, 10 threads, rated at 10,000 messages per hour, no mail merge), you can make these two items disappear. If you know Post.Office well, let me know and we can revisit the issue. All these pieces are services (on Win2K) and you can start, stop, and/or disable them easily. You don't have to uninstall anything until you're happy with the result. The Business Mail Gateway that you may have seen is just that, a gateway rather than a mail server. As such, I don't think it will be able to solve the problem, since the relaying will still occur and if such relays have nulls in the envelope and header, the same sites will probably reject the messages. Hope this helps, George Radford [log in to unmask]