It doesn't return the mail, just a brief bounce message, and that can be turned off. As I mentioned, it can be good to let legitimate people know their email didn't go through, but it's up to the admin to determine which way they want it. John At 02:07 PM 11/1/2006, you wrote: >"LISTSERV site administrators' forum" <[log in to unmask]> >wrote on 11/01/2006 01:03:09 PM: > > > It can be configured not to return bounces. For non-listserv > > installations, returning bounces does perform the useful task of > > informing legitimate people that their email did not get through and > > they can then take appropriate action. It's possible to mount a > > reverse attack, i.e. have some poor unsuspecting individual get > > thousands of real bounces because their email address was used in one > > or more large spam mailings. > >Returning bogus mail is just plain wrong. The trick is to *NOT* accept >it. This requires evaluating messages DURING the connection, before >returning "250 message accepted". Any of the spam filters based on >sendmail's milter interface can do this. Other MTAs may be able to do >this as well. Closing the connection and then evaluation is going to >guarantee either lost mail or backscatter spam.