Periodically, I go through and remove those members whose messages are
"bouncing" (that is, they're coming back to Yahoo as undeliverable).
I did another general sweep this afternoon.
Should you ever find yourself "removed" from the list (and you haven't
received an email with warnings from one of the mods), it's probably
for this reason. You're not in trouble, but you may want to check and
be sure your MAILBOX isn't full before you rejoin. Often messages
"bounce" if the mailbox is "over quota."