> Couple of our list with over 175 subscribers having problem delivering > messages to all of its members. Some of the messages gets delivered but > not all. WE have not modified the list configuration and were advised to > check for "number of recipient per message" and MAXBSMTP was set to 1000. > > We never had any problem of this nature before and I am not sure what has > caused this error message (552 5.5.3 Too many recipients). It's always best to post the entire error message so a proper answer can be given. MAXBSMTP=1000 is pretty typical for a Windows installation. However, this just means that LISTSERV will bundle a max of 1000 recipients per message (*.mail file) to the outbound MTA. It's the MTA that bundles up the recipients for final delivery. ISPs like AOL, Yahoo and the like will reject a message which has over something like 25 recipients per message. Some even as low as 15. I don't know which MTA your LISTSERV host is using, but I do know that L- Soft's MTA (LSMTP) can easily configure individual SMTP destinations to any number of recipients needed for the mail to get through. By default, LSMTP will send 1 message regardless of the number of recipients. So if you have 100 AOL'ers, that message would be rejected. If you set AOL to a Max of 20, then 5 messages would be sent with 20 recipients each, and the mail would be accepted.