Quote:
Originally posted by David MacQuigg
This might make sense if they are following a "strictly chronological" rule. ... Could you show us a sample of these headers, and a description of what is happening at each step?
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Here's an example (with real email addresses slightly munged). One thing worth noting is that X-linkname is a header prepended by MessagingEngine.com while X-Message-Status was added by Hotmail. About the only way to know this is to see many such headers and understand what each service is doing. What is happenning is that a user (myself) set a FastMail (a.k.a. MessagingEngine) account to periodically pull new email from a Hotmail account (so actually the header lies when it says the protocol is POP3). The fetched email is then injected into the incoming mail stream and delivered (using LMTP) to the IMAP server (which then might redirect it or a copy elsewhere depending on the user's filtering rules).
Code:
Return-Path: <books@honestperkpals.con>
Received: from imap1.internal (store1m.internal [10.202.10.1])
by store1m.internal (Cyrus v2.3.7-fmsvn9682) with LMTPA;
Mon, 20 Nov 2006 01:07:40 -0500
X-Sieve: CMU Sieve 2.3
X-Spam-score: 1.6
X-Spam-hits: HTML_MESSAGE, MIME_HTML_MOSTLY, MPART_ALT_DIFF, SARE_HEAD_HDR_XSIDPRA,
X_MESSAGE_INFO
X-Resolved-to: hadaso@domain.tld
X-Mail-from: books@honestperkpals.con
Received: from services.msn.com [64.4.60.7] by messagingengine.com
with POP3 for hadaso@domain.tld; Mon, 20 Nov 2006 01:07:38 -0500
X-LinkName: hotmail
X-Message-Status: sF:0
X-SID-PRA: University of Phoenix <books@honestperkpals.con>
X-Message-Info: LsUYwwHHNt2RlBaBm/dUNFMqf6y+DHODEmxfFPFGtm0=
Received: from honestperkpals.com ([208.100.6.244]) by bay0-mc1-f16.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2444);
Sun, 19 Nov 2006 21:00:15 -0800
Received: by honestperkpals.com id hc4r8809bo4s; Sun, 19 Nov 2006 23:00:18 -0600 (envelope-from <books@honestperkpals.con>)
Reply-To: "University of Phoenix" <books@honestperkpals.con>
From: "University of Phoenix" <books@honestperkpals.con>
To: <hadaso@hotmail.con>
Subject: Earn your Degree
Quote:
Originally posted by David MacQuigg
But I'm a little surprised that an MTA is using POP to transfer mail. Usually SMTP is the protocol between MTA's, and POP is used by the recipient to fetch mail from the destination MTA.
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In this case Hotmail is assuming that they are the destination MTA but they are not. Anyway, I have not really checked the facts, but I think POP was designed to allow the delivery of email to email systems that are disconnected from the Network most of the time. That is, the email for the destination is routed to an accessible host, and then the MTA for final destination is setup to pull the email for its users from the server that holds them and delivers them to the users' mailboxes. In the early days mail was delivered to the computer where the user account was hosted and the user logged in and read the mail on that computer (such as by using the unix "mail" command). A system that was connected most of the time didn't need POP since mail could be delivered directly to the recipient's machine.