On Mon, 7 Jun 2004, Stuart D. Gathman wrote:
For those of us with a Real Operating System(tm), the MTA and MUA are
often on the same machine. For those running a M$ client OS connected
to a remote mail server, you are right that implementing the anti-forgery
protocols in the MUA would not be effective in saving bandwidth. If
I were managing that remote mail server, I would probably do it in the LDA.
Actually, in either case implementing it in the MUA is less desirable. If
you implement it in the MTA, you can detect the forgery during the SMTP
session and reject the mail. If you detect the forgery in the MUA, you've
already accepted the mail and your only options are to bounce it or
silently drop it.