There may be a few reasons why this is happening. A "Mail Delivery Subsystem" message indicates that mail you
have sent was not delivered to the intended recipient. This automatic message includes a copy of the mail that
could not be delivered, and a description of what went wrong. If, after reading the message details, you are still
unclear about why your mail was returned, you can forward one of these "Returned Mail" messages with full headers
(see "What Are Full E-mail Headers?" in this issue of Connect) to the
ITS Client Services Center (its.clientservices@nyu.edu). We can
tell you why the message was returned.
If the message from the Mail Delivery Subsystem describes a message that you never sent in the first place, it
is possible that a virus might have sent the message without your knowledge. Whether or not this is the case,
you should install and update an anti-virus program on your computer, and run a full system scan. (A complimentary
copy of Norton AntiVirus is available to the NYU community at
http://www.nyu.edu/its/software/). Since new viruses
emerge nearly every day, you should also make sure that your virus definitions are up to date. For assistance
with updating your virus definitions, use the Help menu in your anti-virus software.
It is also possible that the "Returned Mail" message is the result of a virus that is not on your computer,
but on the computer of someone to whom you have previously sent e-mail. Many of the viruses circulating today
are able to scan a whole computer for e-mail addresses (whether in an address book, a message, or a web page)
and then send themselves to those e-mail addresses, further spreading the virus. When viruses do this, they
often substitute the address that appears in the "From:" line. This way, when a message is returned to the
address on the "From:" line, it will go to whichever address the virus has inserted there, even though that
person never sent the message in the first place. If, as described above, you send a copy of the "Returned Mail"
message to the ITS Client Services (again, with full headers) we can help you determine whether this is the
problem. If the message is being generated because of a virus-infected machine elsewhere, NYU will contact the
Internet Service Provider of the computer that is sending out this virus, so they may take steps to stop it.
There is also the possibility that you are subscribed to a mailing list that is attempting to deliver mail
and is, for some reason, failing. Examining the returned message details would help you determine that. If
this seems to be the case, you can contact the appropriate "listmaster" (keeper of the mailing list) to
alert them to the problem.
In answer to the last part of the question, ITS can not block messages from "Mail Delivery Subsystem".
Blocking such messages would prevent you from knowing that one of the problems described above was taking place.
If you would prefer not to have to delete these messages manually, you can set up an e-mail filter in many e-mail
programs. The details vary by program, but, in general, filters can be configured to delete these messages or
move them to a specific folder. The ITS Client Services Center (1-212-998-3333 or
its.clientservices@nyu.edu) can help you do this.
