Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site hou3c.UUCP Path: utzoo!watmath!clyde!burl!hou3c!don.provan@CMU-CS-A.ARPA From: don.provan@CMU-CS-A.ARPA Newsgroups: net.mail.headers Subject: Re: What are SMTP commands "EXPN" and "VRFY" good for? Message-ID: <17Sep84.133744.DP0N@CMU-CS-A.ARPA> Date: Mon, 17-Sep-84 13:37:00 EDT Article-I.D.: hou3c.838 Posted: Mon Sep 17 13:37:00 1984 Date-Received: Thu, 4-Oct-84 02:46:35 EDT Sender: ka@hou3c.UUCP (Kenneth Almquist) Lines: 17 To: Rich WalesCc: Header-People@MIT-MC.ARPA In-Reply-To: "Rich Wales's message of 15 Sep 84 16:39-EST" i've always assumed that VRFY would be used only in reaction to a user's request. in other words, a user would say "verify jones@cmu-10a" and the program would run out and check on the existence of such a user. there are any number of reasons a person may want to check an address in such a way. for me, it's usually because i can't remember whether jones has his mailbox on cmu-10a or cmu-10b. VRFY allows me to check this without actually sending mail. i assume EXPN is for similar purposes. it's not intended to be used to deliver mail to the list. it allows a user to find out who's on the list. i didn't have anything to do with designing this protocol, so i'm guessing when i say "intended", but it certainly seems like the more obvious use of optional commands. i'd also like to point out that i talk big, but none of my software uses or supports these two commands in any way.