>Recently I was  alerted byORBS.ORG that my site had been identified as being
>an email relay site, i.e. it could be used by spammers to relay messages to
>other sites.  I plugged up all the holes, including an empty from address
>which
>ORBS.ORG tests for, since many spammers don't include a FROM address.
>
>However, an unexpected result of this was that I no longer could receive mail
>from the LISTSERV account.  This is because it sends a blank address in the
>MAIL FROM: command in the SMTP protocol.  I.e.:
>
>MAIL FROM:<>
>
>A real address is specified in the message header itself.   I believe that
>more and more people are going to testing for this situation.  Is there a way
>to correct LISTSERV to specify the address in the MAIL FROM: command also?
>Thanks.
>
>Mark

Read RFC821 before you ask for this type of thing.

An empty From, e.g.

From: <>

violates RFC822 and is a pretty sure sign of either a spammer or a broken
mailer, but an empty MAIL FROM:

MAIL FROM: <>

is not only allowed but is generally required in a situation where you
don't want bounces to go to any addresses.  (For instance, a bounce message
itself generally will have an empty MAIL FROM to avoid mail loops.)

I suggest you correct your MTA's broken configuration.

-jwgh