I'm a non-expert list owner running an announce-only list using 1.8d.  It
seems that some of my subscribers receive postings at institutions which
have recently begun to filter spam more aggressively with the result that
list postings are no longer getting through to them.

I've told these subscribers that they need to have their institution
whitelist the email addresses of the list editors.  Obviously I can't do
much on my end, but I wanted to know if this is a common experience and if
there's anything at all that I can do to reduce the chances of list postings
being misidentified by spam filters.

Thanks...
Rob