>SMTP session. I'm hearing a reasonably strong consensus that it is now >acceptable -- and possibly essential -- to do some serious processing before >responding.
Yes, definitely. One of the reasons people hate my favorite MTA, qmail, is that it implemented the advice to respond as fast as possible, queued incoming mail immediately, and deferred all rejections until later, even invalid mailboxes. I, and most other qmail admins, have replaced the standard SMTP daemon with one that does a lot more, in my case including DCC lookups and spamassassin, as well as most invalid user rejections, before responding to the client. R's, John
