Garbled mails in Maildir storage

[Florian Lohoff]

Hi,
from time to time i am having mails delivered to my anon maildrop
which completely break mailbox listing.

I ignored it mostly as this is an anon maildrop for one time emails so
loosing spam wasnt an issue. Today i had a mailbox which wouldnt list at
all which was caused by 50 consecutive mails beeing broken.
(I am showing the last 20 in the web interface)

After some debugging i found a bunch of mails like this:

	Return-Path: <*************************>
	X-Original-To: test at wasteland.rfc822.org
	Delivered-To: inbox at wasteland.rfc822.org
	Received: from node11.tmdvps.com (unknown [184.154.211.109])
		by pax.zz.de (Postfix) with SMTP id 3B73DD00B5
		for <test at wasteland.rfc822.org>; Thu,  8 Jun 2017 17:09:25 +0200 (CEST)

	<U+FEFF>Date: Thu, 8 Jun 2017 10:09:24 +0000 (GMT)
	From: Apple Support <*************************>
	REPLY-TO: do_not_reply at apple.com
	To: test at wasteland.rfc822.org
	[ ... ]

Yes - there is an UTF-8 BOM in the middle of the mail header. Breaks parsing of
the mail header of dovecot. No From and To in the listing.

And i found even more:

	Return-Path: <**********************>
	X-Original-To: test at wasteland.rfc822.org
	Delivered-To: inbox at wasteland.rfc822.org
	Received: from 36.248.164.233 (unknown [36.248.164.233])
		by pax.zz.de (Postfix) with SMTP id B2B0F1000FF;
		Tue, 22 Jan 2019 10:37:35 +0100 (CET)
	Received: from 6.51.138.64 by ; Tue, 22 Jan 2019 04:36:35 -0500
	Message-ID: <B[20

Mails that end with garbage in them middle of the mail header. This is a standard
Maildir storage using the dovecot transport via postfix.

Does anyone have an explanation for these kind of mailstorage breakage? How could broken
mails like this even be processed by postfix, dovecot deliver etc.

As the last mail is pretty current i quickly grepped the postfix logs:

Jan 22 10:37:35 pax postfix/smtpd[20269]: B2B0F1000FF: client=unknown[36.248.164.233]
Jan 22 10:37:37 pax postfix/cleanup[20371]: B2B0F1000FF: message-id=<B[20
Jan 22 10:37:37 pax postfix/qmgr[9371]: B2B0F1000FF: from=<**********************>, size=233, nrcpt=2 (queue active)
Jan 22 10:37:37 pax postfix/pipe[19192]: B2B0F1000FF: to=<inbox at wasteland.rfc822.org>, orig_to=<test108 at wasteland.rfc822.org>, relay=wasteland, delay=2.2, delays=1.7/0/0/0.41, dsn=2.0.0, status=sent (delivered via wasteland service)
Jan 22 10:37:37 pax postfix/pipe[21064]: B2B0F1000FF: to=<inbox at wasteland.rfc822.org>, orig_to=<test at wasteland.rfc822.org>, relay=wasteland, delay=2.2, delays=1.7/0.01/0/0.48, dsn=2.0.0, status=sent (delivered via wasteland service)
Jan 22 10:37:37 pax postfix/qmgr[9371]: B2B0F1000FF: removed

So even postfix found the message id to be truncated.

Does dovecot have a "broken maildir mail storage mail dictionary" for automated tests?

Flo
-- 
Florian Lohoff                                                 f at zz.de
        UTF-8 Test: The 🐈 ran after a 🐁, but the 🐁 ran away
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