On Tue, 27 Feb 2001 16:40:03 -0500, Peter K Robinson <[log in to unmask]>
wrote:

>Basically what does passive probing actually do,  and will it assist in
>auto-deletion or does it do something else ?

Yes, it can assist in auto-deletion, especially for forwarded address recipients
(where the error bounce comes back from or showing a different address than the
one subscribed to the list and which was used to send the mail out.)

It does this by encoding the address-as-mailed-to into the RFC821 Return-Path:
address (MAIL FROM:<address>) in a special way so that when the bounce returns
to LISTSERV, it will have the server name, the listname and the
address-as-mailed all together and LISTSERV does not have to try to interpret
non-standard reply message formats, etc.  

For example:

Return-Path: <owner-survey*bparker**WNT*-DC*-LSOFT*[log in to unmask]>

However, as you are running LISTSERV on unix, sendmail cannot correctly handle
this form of return-path address without modification.  The necessary mods are a
user-contributed script on our FTP server, but you need to make them.  If you
are using other than sendmail, you should look at the mods and figure out how to
accomplish the same for your other favorite mail program.

So, for LISTSERV/unix the default is to disable passive probe anyway, so it
doesn't really matter what settings you use.

>I'm also a little confused with the manual which says that probe(30) is a
>default value for lists <1-2K - and to switch it off requires probe(0) in
>the header.  

Yes.

>Is this saying that probe(30) will be active if I have it in
>my header line (as above) and it will also be active if I delete the probe=
>component from the auot-delete command altogether, and that the only way to
>switch it off is to include probe(0) ?

Yes, that is what it means, for Windows.  For unix, the default is to disable
Passive Probe at the server level because the default sendmail can't handle the
returned mail.

For more information, see DEFAULT_PROBE in Appendix C of the Site Mgr Manual.