Conference forty2::mailbus_400

3126.0. "Netscape sets Sender so reply via SMTPGW goes astray" by ZUR01::ASHG (Grahame Ash @RLE) Wed Feb 05 1997 13:02

Is our SMTP Gateway responsible for this problem? This was reported to a 
customer (Ciba) by the "postmaster" of a site they exchange mail with:

> A user here is using netscape to send mail to a contact at ciba.
> He can't receive mail on this machine so he has set his mail
> address in his netscape preferences to that of another account.

> So he sends a mail to ciba; the only reference to his lister
> account in the outgoing mail is the line Sender: [email protected]
> Everything else refences his mail account. The ciba user is
> of the form [email protected] and is a MSM user in IS 2.4.

> The problem is that the software that translates the address into
> microsoft mail format takes this Sender line as the address
> that should be replied to and of course the ciba user cannot reply
> and I get lots of postmaster mail.

> Sender: is only a record of who actually sent the mail; it should
> never be used as a return address (RFC-822).

I believe the mail is routed:

Netscape -> SMTP -> MB400 SMTP Gateway -> MTA -> MS-Mail X.400 Gateway

I looked up RFC822, but also looked at RFC1327, where this is stated:

  2.2.1.  Origination in RFC 822

     A mechanism of mapping, used in several cases, is to map the RFC 822
     header into a heading extension in the IPM (InterPersonal Message).

  [deleted]

     From:
          Supported.  For messages where there is also a sender field,
          the mapping is to "Authorising Users Indication", which has
          subtly different semantics to the general RFC 822 usage of
          From:.

     Sender:
          Supported.

  and, from 5.1.3: (which deals with the IPM header)

     From:
          If Sender: is present, this is mapped to
          IPMS.Heading.authorizing-users.  If not, it is mapped to
          IPMS.Heading.originator.  For this, and other components
          containing addresses, the mappings of Chapter 4 are used for
          each address.

     Sender:
          Mapped to IPMS.Heading.originator.


So, it seems to me that if both fields are present, that the Gateway MUST
map Sender to Originator, and I imagine that the MS Mail environment will
generate a Reply to Originator rather than to the Authorising Users.

fwiw, I tried to reproduce this, and couldn't get Netscape to write a Sender 
field.

Any opinions on who might be to blame here? Suggestions for a fix? All I've 
come up with so far is that the Netscape sender should add his/her mail 
address as a Reply-to.

Thanks,

grahame