> Our computing facility, running PMDF over VMS mail, is acting as the mail
> gateway to the Internet for another organization's GroupWise mail system.
> The mail gateway between our systems is the GroupWise API running on a PC
> attached to both networks. As the recipient of mail from the PMDF
> Postmaster, I have been involved in numerous mail loops created by
> automatic vacation notice replies generated in GroupWise with headers
> requesting delivery and/or read receipts.

> The loop usually starts with the GroupWise user sending the vacation
> notification message to an incorrect e-mail address which results in a
> message from the PMDF Postmaster regarding the error. This generates an
> automatic reply from the GroupWise user account. The Postmaster responds
> to the attached receipt request(s) which generates another automatic
> reply.....

Apparently WPO normally sends those "on vacation" messages in response to _all_ messages, including receipt/bounce messages. This then leads to the kind of looping you've seen. The fact that WPO sends them to all messages is in some sense the source of the problem: if WPO kept track of who it had already sent the "on vacation" message to, or didn't send it in response to notification messages such as receipt or bounce messages, there wouldn't be much of a problem even if WPO wanted to request a delivery receipt for the original "on vacation" messages.

However, given the way WPO sends out the "on vacation" messages, you end up having to address the issue of the delivery receipts. Jim Becker <BECKERJA@sysadm.suny.edu> posted a message to the info-pmdf list in May saying, in part:

< The problem arises because the Status Information request
< that Groupwise uses (under Send Options, Status Information) is
< translated into a Delivery- and/or Read-Receipt header line as a
< message passes through to the outside world.
<
< When you have a GW Rule defined to automatically reply to incoming
< mail, it includes ALL mail even delivery receipts hence the loop.  We
< periodically deal with this and it is particularly nasty when a
< Listserver gets involved.  The GW rule and the Listserver argue back
< and forth, unnoticed sometimes for days, creating several thousand
< messages back and forth.  The worst part is when the cleanup is done
< and status updates are generated for the delete and purge of each
< redundant message.
< 
< The fix is to set Status Information to None when the rule is
< activated AND perhaps even unchecking "Insert in Out Box" so that if
< a loop does occur, half the clean up deletes (those from the OutBox)
< don't have to take place.

I've never tried it myself, but presumably disabling the Status Information when WPO users are using the vacation rule would prevent at least some cases of looping messages (e.g., due to WPO requesting a delivery receipt for the "on vacation" message itself, resulting in the delivery receipt triggering yet another "on vacation" message, etc.).

However, you may still see other problems with receipt requests from WPO. If so, you can, if you wish, have PMDF drop all receipt requests going to/from WPO; see below.

> I'm trying to sort out how to prevent future occurrences of these message
> loops, but don't understand the generation of these receipt requests at
> the interface between PMDF and GroupWise. Where are GroupWise message
> status requests translated into message header entries; in GroupWise, at
> the GroupWise API gateway, by PMDF (although I don't see how)? 

By default, PMDF turns WPO's Status Information requests into the usual Internet way of sending receipt requests (particular headers). The (not yet documented) SUPPRESS_READ_RECEIPTS=1 and SUPPRESS_DELIVERY_RECEIPTS=1 options in your WPO_LOCAL_OPTION. file can be used to tell PMDF to drop such receipt requests going to or from the WPO channel.

>                                                                Does PMDF
> do translations of header entries from other mail systems to comply with
> some RFC standard? 

PMDF currently uses the headers that are sort of a defacto standard for Internet receipt requests and recognizes some variant headers on incoming messages; however, there is some actual standards work (NOTARY) for handling bounce messages and delivery receipts (the last I heard, read receipts handling is still an open topic) and PMDF V5.1 will be supporting these new standards.

>                        If there's something I can do within PMDF, great,
> otherwise I need to explain to the GroupWise administrators the process
> that creates these e-mail loops so that they can fix the problem.
> Thanks.

I'd suggest having the WPO administrators check that Status Information requests are being disabled when the vacation rule is being used.

But if that doesn't turn out to be sufficient, you can use PMDF's SUPPRESS_*_RECEIPTS options to disable receipts <-> WPO entirely.