Yep, they're
real.  Since you sent your inquiry to the LML at large I'll respond in kind... this way everyone gets a reminder of what they're all about.
 Anyway, here's the post I send to everyone who asks about them...;

"""

These warning
messages are generated by the LML listserver anytime an LML message is bounced back to it.  They are used to detect inactive email addresses...
after 5 of these warnings go unanswered the email address in question is unceremoniously removed from the subscription rolls, ostensibly because the
email address is no longer valid.  The bounces may be caused by delays in your ISP's mail server, by an outage in a router somewhere between here
and there, or just a clog in the internet backbone somewhere along the way.  The only time they are the fault of the recipient is if his email
server is volume limited and the subscriber fails to empty his email box on a regular basis.  Regardless of the reason, dealing with these
warnings is an extremely simple matter... whenever you get one, just reply to it.  You don't need to write anything into the message, you don't
need to modify the address or any of the headers, just hit the reply button and send off whatever it is that shows up in your reply editor... all the
listserver is looking for is the reference number contained in the subject box of the headers.  After you've sent the reply on its way, simply
delete the original message and go on about your business.  With most email programs, taking the necessary steps to address one of these warnings
typically takes no more than a few seconds... reply, send, delete.  That's it.  Failure to reply to at least one in five of these messages
will result in your LML subscription being removed.

If the reply, send,
delete option is too much to ask, then your only other option is to remove your normal subscription, switch to the null mode and do your reading of
the LML on the website archives.  The null mode stops all deliveries of LML emails to your mailbox but retains your email address as a valid one
for posting purposes.  The decision is up to you.   The one thing I can't do is make the warnings stop as long as you're a regular
subscriber. They happen, it's just a fact of life.  Sorry about that.
"""

So there you go.  I hope this
helps.

  <marv>


"William A. Hogarty" <billhogarty [at] gmail.com>
wrote:

> Please confirm that the lml warning messages I am receiving are valid.
>
> Thanks, Bill
Hogarty