I learned yesterday that mail from all [log in to unmask] addresses will
now show that they are coming from [log in to unmask]  A notice
was made available to people who logged into the MSN web pages, but not
sent by email.  This is part of MSN's conversion to a standard POP3
email system in the near future, which will use a different domain name.

This means that MSN members of your lists won't be able to post messages
or change status without list owner assistance, and they may not realize
that their address has changed.