Charles Gregory wrote:
... but any legitimate mail that is blocked will result in their MUA (Outlook) displaying an error message. This is GOOD. :)
My experience has been that Outlook in particular (not Outlook Express or its descendant Windows (Live) Mail) does NOT in fact display SMTP error messages exactly as the server spits them out. :( A few other MUAs also commit this stupidity.
(I agree with your main point about rejecting while the connection is open instead of generating DSNs for spammy mail though.)
-kgd
