Received: from localhost (daemon@localhost) by CS.UTK.EDU with SMTP (cf v2.9s-UTK) id UAA12531; Tue, 28 Jul 1998 20:00:11 -0400 (EDT) Received: by cs.cs.utk.edu (bulk_mailer v1.10); Tue, 28 Jul 1998 19:59:59 -0400 Received: by CS.UTK.EDU (cf v2.9s-UTK) id TAA12482; Tue, 28 Jul 1998 19:59:59 -0400 (EDT) Received: from resnick1.qualcomm.com (resnick1.qualcomm.com [206.139.85.98]) by CS.UTK.EDU with ESMTP (cf v2.9s-UTK) id TAA12454; Tue, 28 Jul 1998 19:59:49 -0400 (EDT) Received: from resnick2.qualcomm.com (206.139.85.99) by resnick1.qualcomm.com with ESMTP (Eudora Internet Mail Server 2.1); Tue, 28 Jul 1998 18:59:39 -0500 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-Sender: resnick@resnick1.qualcomm.com Message-Id: In-Reply-To: <19980728230814.2120.qmail@cr.yp.to> References: X-Mailer: Eudora [Macintosh version 4.1a14-8.98] Date: Tue, 28 Jul 1998 18:59:37 -0500 To: "D. J. Bernstein" From: Pete Resnick Subject: Re: suddenly closing connections Cc: drums@cs.utk.edu On 7/28/98 at 11:08 PM +0000, D. J. Bernstein wrote: >> > > An SMTP server MUST NOT intentionally close the connection except: >> > Sorry, but you're asking for something impossible. Servers can crash. >> Crashes are not intentional. > >That depends. What if a sysadmin deliberately turns the machine off? >What if he kills the server process? What if he sets up a script to kill >the server process? What if the OS vendor distributes that script? What >if the script is integrated into the server? I would consider these all "as if the server crashed". That is, the SMTP server, as such, is not intentionally closing the connection without sending the 451. >Anyway, my concern is interoperability; intent is irrelevant. Quite. And servers closing connections without 451's were causing serious heartburn to some clients. Server writers need to be made aware of that interoperability issue and not do such things if they can help it. On the other hand: >The client has to be ready for the server to close the connection at any >moment. That is already stated quite clearly at the end of that section: SMTP clients that experience a connection close, reset, or other communications failure due to circumstances not under their control (in violation of the intent of this specification but sometimes unavoidable) should, to maintain the robustness of the mail system, treat the mail transaction as if a 451 response had been received and act accordingly. pr -- Pete Resnick QUALCOMM Incorporated Work: (217)337-6377 or (619)651-4478 Fax: (217)337-1980 or (619)651-1102