[imp] Re: "Return-Path" header?

[Michael M Slusarz]

Quoting Liam Hoekenga <liamr at umich.edu>:

| Hey guys -
| 
| We're running into a big problem with bounce / redirect and our
| openldap managed email groups.  It's seems to be the value of
| "Return-Path" that's confusing things.  Does IMP always set Return-Path
| to the "From" header value?
| 
| IMP doesn't seem to alter the original Return-Path when you bounce
| mail, and that prevents message that are being sent to moderated groups
| from being seen by anyone but the moderators.

IMP is just trying to be RFC compliant - which can be all sorts of 
confusing.  From RFC 2822 [3.3.6]:

   Resent fields SHOULD be added to any message that is reintroduced by
   a user into the transport system. . . . **No other fields in the message 
   are changed when resent fields are added**.

BUT, from RFC 2821 [4.4]:

   The primary purpose of the Return-path is to designate the address to
   which messages indicating non-delivery or other mail system failures
   are to be sent.

It appears that we should strip out the existing Return-Path header since, 
obviously, we don't want these failure messages for example to go to the 
original sender.  However, this would violate a literal reading of RFC 
2822 - since NO other fields are supposed to be changed.

I think I will go ahead and make the change, and if anyone else has an 
opinion on this, it would be great to hear.

michael

________________________________________
Michael Slusarz [slusarz at bigworm.colorado.edu]
The University of Colorado at Boulder