<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <HTML> <HEAD> <TITLE> [fetchmail]fetchmail vs Maillenium; mail truncated to 80K </TITLE> <LINK REL="Index" HREF="index.html" > <LINK REL="made" HREF="mailto:jcfoley%40comcast.net"> <META NAME="robots" CONTENT="index,nofollow"> <LINK REL="Previous" HREF="008522.html"> <LINK REL="Next" HREF="008524.html"> </HEAD> <BODY BGCOLOR="#ffffff"> <H1>[fetchmail]fetchmail vs Maillenium; mail truncated to 80K </H1> <B>jcfoley@comcast.net </B> <A HREF="mailto:jcfoley%40comcast.net" TITLE="[fetchmail]fetchmail vs Maillenium; mail truncated to 80K">jcfoley@comcast.net </A><BR> <I>Fri, 23 Apr 2004 02:51:22 +0000</I> <P><UL> <LI> Previous message: <A HREF="008522.html">[fetchmail]fetchmail vs Maillenium; mail truncated to 80K </A></li> <LI> Next message: <A HREF="008524.html">[fetchmail]fetchmail vs Maillenium; mail truncated to 80K </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#8523">[ date ]</a> <a href="thread.html#8523">[ thread ]</a> <a href="subject.html#8523">[ subject ]</a> <a href="author.html#8523">[ author ]</a> </LI> </UL> <HR> <!--beginarticle--> <PRE>You're probably using a Comcast POP3 server. Many others have experienced this problem. The problem is that the server truncates the amount of data returned by the POP3 TOP command. Comcast changed to the Maillennium POP3 server in Summer 2003. For several months they refused to acknowledge any issue at their end that would account for email truncation. Recently the Comcast Government Affairs Manager at Comcast of Montgomery (Maryland) sent me the information at the end of this message. I believe the Outlook Express flaw they reference was fixed a few years ago. Regardless it does seem to be a strange and non-conforming server implementation that silently does the wrong thing specified by the RFC and every other server I've used. On the other hand, people have made the comment that fetchmail should not be relying on TOP because a) that's not what it is for and/or b) it is an optional POP3 command. Item I8 of the fetchmail FAQ which appears to be maintained by Eric S. Raymond says, "Don't mistake this for a fetchmail bug." It would be nice to hear from a fetchmail expert/authority on whether fetchmail is doing the right thing by using TOP and for a rationale of the FAQ's response. If fetchmail's use of TOP is legitimate then maybe Comcast would uncripple their server if more people complained. Jim Foley ======================================================================= ======================================================================= Date: Wed, 3 Mar 2004 11:59:17 -0500 Mr. Foley, this email responds to the questions you posed following our conference call. First, Comcast does support POP 3 TOP commands, however Comcast has found that increasing the amount of data TOP returns beyond the value of 64K has a tendency to crash Microsoft Outlook Express when an abnormally large header is sent. Increasing the value beyond 64K would open the platform to malicious use of large headers that adversely impacts system performance. Virtually all of Comcast's high-speed Internet customers use Outlook Express. Comcast has not received requests from other subscribers who seek to use the TOP command in the manner you have requested. Further, Comcast has not received any other complaints regarding email truncation with the TOP command. Should you wish to continue checking your mail through manual commands you might try using the RETR command, which will return the entire message. ... Date: Fri, 5 Mar 2004 16:28:11 -0500 Mr. Foley: This is in response to your question regarding "POP 3 RFC compliance." We have tried to answer your question about Comcast's services by talking about the specific application in which you are interested and how that application relates to technical information regarding the configuration of Comcast's Internet service. We have provided you all the information that we can by explaining that Comcast limits the optional POP 3 Top Command to a value of 64k because any larger value has a tendency to crash Microsoft Outlook and could leave Comcast's system open to the malicious use of large headers intended to impair system performance. The decision by Comcast to place limitations on the optional POP 3 TOP email commands is a technical business decision made by Comcast in the best interest of all its customers and its system. ... ... With respect to the specific RFC at issue, RFC 1939, POP 3, it is our understanding that it is a protocol "intended to permit a workstation to dynamically access a maildrop on a server host in a useful fashion. Usually, this means that the POP3 protocol is used to allow a workstation to retrieve mail that the server is holding for it. Pop 3 is not intended to provide extensive manipulation operations of mail on the server." POP 3 was created in May 1996 and has not been revised since, despite the many changes in computer hardware and software related to handling of email since that time. In any event, the TOP command is identified as an optional POP 3 command in RFC 1939. ... </PRE> <!--endarticle--> <HR> <P><UL> <!--threads--> <LI> Previous message: <A HREF="008522.html">[fetchmail]fetchmail vs Maillenium; mail truncated to 80K </A></li> <LI> Next message: <A HREF="008524.html">[fetchmail]fetchmail vs Maillenium; mail truncated to 80K </A></li> <LI> <B>Messages sorted by:</B> <a href="date.html#8523">[ date ]</a> <a href="thread.html#8523">[ thread ]</a> <a href="subject.html#8523">[ subject ]</a> <a href="author.html#8523">[ author ]</a> </LI> </UL> </body></html>