We've had a go-round on this before, and the general feeling is that it
is not a very good idea.  I do know that my university does it for a
faculty news list, but they use the following (probably from a perl script):

- the list is set to notify the list owners that someone has unsubscribed.
  and that notice is copied to a file
- at midnight the script scans the file for addresses that have removed
  themselves
- these addresses are then added again, using "quiet" so the addresses
  don't know until they get more mail
- the script deletes the file that stores the removal notices

I gather there has been some acrimonious discussions involving people who
have removed themselves half a dozen times, and finally confronted the
person who manages the list, who has removed them manually.

> Anyone have a down and dirty way of not allowing anyone to remove
> themselves from a list, in other words blocking users from getting off a
> list, and making them a captive audience.
>
> Kevin

--
Dr. W. Schipper                     Email: [log in to unmask]
Department of English,              Tel: 709-737-4406
Memorial University                 Fax: 709-737-4528
St John's, Nfld. A1C 5S7