qconfirm - benefits
No content scanning
Small code size
qconfirm does not look at the contents of the message. It just looks at the envelope, more precisely the envelope sender address, which qmail has thankfully put into the environment variable SENDER.
qconfirm does not read, write, copy, move, or deliver a message. It just decides what to do with the message and tells qmail-local on each delivery attempt. If qconfirm defers a delivery because it has requested a delivery confirmation, the message isn't read, or copied, or such, but stays in the qmail queue. The delivery will be tried again in a little while.
Content scanning can consume a lot of resources, and normally needs some validation system, which eventually produces more or less false positives. Also such validation systems normally need to be maintained and should be updated regulary. qconfirm does not depend on such a validation system.
qconfirm can be configured to process bounces of delivery notifications it sends, and so reduces the amount of doublebounces delivered to the postmaster's mailbox. See Handling bounce messages for details.
This minimizes the possibility of bugs introduced by programmer's fault, and makes it more easy for people to proofread the source code.
Gerrit Pape <email@example.com> $Id: benefits.html,v 1.2 2003/01/06 12:35:58 pape Exp $