The problem here seems to be that many of you don't understand the concept
of peering.  You should only be subscribed to one of the peers, not
both of them.  You should send your mail to the peer you are subscribed
to, not both of them or the non-subscribed one.  (If you're getting
double acks you may be subscribed to both peers, one with NOMAIL, the
other with MAIL.)

Peering a list is done when you want to keep archives in two locations
or when it makes sense to have more than one copy of the list in separate
physical locations.  In the latter case we are talking about having (for
instance) a European peer and a North American peer.  This was a lot more
important 10 years ago than it is now because the point was to save
bandwidth by sending a single copy of list mail across the transatlantic
line to be "burst" by the peer for people on the peer's side of the
pond.  Today peering is really not all that useful since bandwidth isn't
the issue it used to be.

We keep this list (and LSTSRV-L) peered in Sweden and DC at least partly
to ensure that peering continues to work :)  If you prefer to post to
the list via the web interface, you need to be subscribed to the peer
in DC (PEACH.EASE.LSOFT.COM) because there is no web interface available
on the Swedish peer (SEARN.SUNET.SE).  Otherwise it is not really an
issue which peer you are subscribed to, although you should always post
through that peer to avoid me having to OK your messages :)  (For instance
for sentimental reasons I am subscribed to the Swedish peer even though
I get my mail in the US, and that's the peer I post through.)

I hope this helps.

Nathan