Claus Assmann: > > With SMTP there is no per-recipiet end-of-data reply, and a > > reject reply will block mail for all recipients. > > AFAICT PRDR can do that -- it's implemented in exim and some other MTA. > However, it's barely used...
It's a chicken and egg thing; if enough systems implement PRDR then it might be used more. I recall that we had a dispute about PRDR Milter protocol support. I wanted to reuse existing protocol elements and avoid implementing PRDR Milter support from scratch. Wietse