Re: Configure Sendmail so receiving systems have good Return-Path header

[Yozons]

Thanks for the help. I'm still working on the javamail mail.smpt.from
property described. I've done that and it's still not setting the
Return-Path on the receiving SMTP server. Perhaps this is the right
route, and I'll keep working various ways to see what it takes. I can
see the name used in the Message-ID header, so it's getting set in
JavaMail, but it's not convincing sendmail to use it when actually
transferring the email to the receiving system.

As part of this rework, I found the following description of having the
Return-Path header set separately for each message sent to help detect
and report back bounces which otherwise would not make it when sending
out emails on behalf of others.

QUOTE (from http://cr.yp.to/proto/verp.txt):
Making VERPs work requires two pieces of local software support.
First: it must be easy to modify the outgoing sender address
separately for each envelope recipient. For example, with one
mailer, qmail, a user can simply touch ~/.qmail-list-owner and
~/.qmail-list-owner-default to apply VERPs to user-list.

Second, and more important: it must be easy to identify a collection
of addresses, such as djb-sos-owner-*, and send all mail for those
addresses to one place, while preserving the * information. Under
qmail, all user-list-owner-* mail will be sent to the user once he
touches ~/.qmail-list-owner-default. Sending the mail through an
automated bounce-handling program is just as easy.
ENDQUOTE

I confess I've never used qmail and do not really know what these do,
but the idea is quite clear.

For each message sent on behalf of another, set the Return-Path on the
receiving system to include the original person's email, such as
[email protected], and then have the
bouncehost.com sendmail store all email to bounce-handler-* into a
single account for processing later. The original email address can be
easily determined by the rest of the user name (bob.boy=sender.com
trivially becomes (e-mail address removed)).

What are these features called in sendmail? This is precisely what I'm
trying to do, and it doesn't seem that it necessarily needs to be done
in JavaMail at all as qmail appears to do it using these list-owner
capabilities.

Or is sendmail not the right tool and I should look at qmail for this
purpose?

 

[Matej Vela]

Thanks for the help. I'm still working on the javamail mail.smpt.from
property described. I've done that and it's still not setting the
Return-Path on the receiving SMTP server. Perhaps this is the right
route, and I'll keep working various ways to see what it takes. I can
see the name used in the Message-ID header, so it's getting set in
JavaMail, but it's not convincing sendmail to use it when actually
transferring the email to the receiving system.

(I see you solved this later.)

As part of this rework, I found the following description of having the
Return-Path header set separately for each message sent to help detect
and report back bounces which otherwise would not make it when sending
out emails on behalf of others. [...]
For each message sent on behalf of another, set the Return-Path on the
receiving system to include the original person's email, such as
[email protected], and then have the
bouncehost.com sendmail store all email to bounce-handler-* into a
single account for processing later. The original email address can be
easily determined by the rest of the user name (bob.boy=sender.com
trivially becomes (e-mail address removed)).

What are these features called in sendmail? This is precisely what I'm
trying to do, and it doesn't seem that it necessarily needs to be done
in JavaMail at all as qmail appears to do it using these list-owner
capabilities.

Or is sendmail not the right tool and I should look at qmail for this
purpose?

qmail has a special hook that allows you to send a message to multiple
recipients with a return path of <[email protected]@[]>, which
it transforms to <[email protected]> on a
per-recipient basis. sendmail doesn't have this feature, mostly because
VERP is considered a job for the mailing list software rather than a mail
transfer agent. Anyway, this isn't much of an advantage -- your client can
encode the recipient in the return path by itself, and it's better in the
long run to have something that works with all MTAs.

Also note that sendmail uses "+" rather than "-" to delimit the subaddress,
so the above looks like <[email protected]>.
With procmail, the default local delivery agent on most Linux systems, the
"bob.boy=..." part is available as $1 (which you will most likely pass to a
script; see procmailrc(5)).