On Wed, 2 Mar 2005 17:32:03 -0500, Doug Essinger-Hileman
<[log in to unmask]> wrote:

>00:00:06 Mail posted via SMTP [to a whole host of people, each listed 
>individually]
>-> RSET
>421 Error: timeout exceeded

I am guessing this is a unix installation.  There is some problem with the
outbound mailer. It may have a limitation on the number of email addresses
it will accept, or it may be trying to do DNS validation of each address in
the BSMTP 'package' sent by LISTSERV (the mta must NOT do so at this time),
or something else.  But this is a serious error and needs to be investigated
and fixed.

This error is probably what is indirectly causing your digest size problem.
It prevents LISTERV from sending the digest out at the proper time, so it
continues to grow.  Some later time the (now larger) digest is able to be
sent.