I already checked with our email system administrators (first thing I do
since we have had issues in the past where our anti-spam/anti-virus
systems got hung up). Nothing on their end.

The last email I got from ADSM-L was 3/2/2005.   I do recall a few
message being echoed-duplicated. I also remember when I sent two posts,
I got nasty-grams from the listserver saying that I was trying to post,
twice, which I was not.

Nothing after that !

Stapleton, Mark wrote:

From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On
Behalf Of Zoltan Forray

My apologies to the list, but I can't seem to do this another way.

Can someone who manages this listserver please contact me.   I
have sent
two emails to Marist and can't seem to get a response.

This is the default behavior. One of the administrators sent a test
message to the list in the last 7 days; see if you can find it. (I
deleted it accidently.)

We (another co-worker is also on this list and has the same problem)
have stopped getting ADSM-L mail since last week.

When I tried SET ADSM-L MAIL, it said I wasn't subscribed.
When I try to
resubscribe, it tells me "550 Invalid user".  When I send a SIGNOFF it
takes a long time for a response and then get the same
Invalid user" error.

Have we been blacklisted for some reason ?

Doubtful. Check to see if your mail administrator has been dinking with
your email account. Since email servers allow multiple usernames to feed
the same inbox, and if your administrator changed the default address
you send out when you post an email, you may be broadcasting an email
address that is not the address you originally subscribed with.
(Happened to me a couple of years ago; a lot of email administrators
don't pay attention to consequences like this.)

--
Mark Stapleton (stapleton AT berbee DOT com)
Office 262.521.5627