tneff@bigfoot.com writes:

"Jay R. Ashworth" jra@baylink.com wrote:

...

I don't see that there *is* any theoretical way to *keep* loads down with VERP, by it's very nature.

If one was willing to extend SMTP again,

Not necessary. If you know the remote MTA supports VERP, you can just send email like this:

    MAIL FROM: <mylist-owner-@mydomain.com-@[]>
    250 mylist-owner@mydomain.com... Sender ok
    RCPT TO: <johnsmith@aol.com>
    250 johnsmith@aol.com... Recipient ok
    RCPT TO: <joerandom@aol.com>
    250 joerandom@aol.com... Recipient ok
    DATA

In other words, no extensions to SMTP are needed other than an announcement in the ESMTP banner that the MTA will take responsibility for expanding VERP addresses. My own feeling is that qmail ought to recognize that it's talking to another qmail server, and send a VERP envelope sender, and multiple envelope recipients.

There's no reason why mailman couldn't use a bulk mailer which sorts users by recipient hostname, knows how to recognize qmail, and uses VERP when it does. It could issue "EHLO hostname" and look for "VERP" (for future use) or else just two lines: 250-ns.crynwr.com NO UCE 250-PIPELINING 250 8BITMIME

If just -PIPELINING and 8BITMIME are present, then it could issue "HELP" and look for the qmail help message: 214 qmail home page: http://pobox.com/~djb/qmail.html

As Barry says, VERP tells you precisely which address is bouncing, but it doesn't say why.

-- -russ nelson http://russnelson.com | The problem with do-gooders Crynwr sells support for free software | PGPok | and governments is that they 521 Pleasant Valley Rd. | +1 315 268 1925 voice | always think the government Potsdam, NY 13676-3213 | +1 315 268 9201 FAX | will choose as they would.