"LISTSERV list owners' forum" <[log in to unmask]> wrote on
09/21/2004 09:07:43 AM:

> 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).

More and more sites are implementing spam filters, and some of them assume
that if a message is received to many recipients, it must be spam.
Unfortunately, many spam filters are seriously flawed, and it seems to
affect list owners disproportinately.

You may need to cut MAXBSMTP down to 5 or so to get through some of the
stricter filters.

As Site Manager, I have started telling list owners, that it's at the
other end, let them know about it, there's nothing I can do.