[Dovecot] dovecot Digest, Vol 91, Issue 18

[Alan Brown]

> From: Timo Sirainen <tss at iki.fi>
> Subject: Re: [Dovecot] emails getting mangled when dragging from
> 	Exchange account to IMAP shared folders

> On Wed, 2010-11-03 at 16:18 -0700, Scott Goodwin wrote:
>> FYI, I got rawlog working and it shows the same break in the raw logs as in
>> the broken headers.
>> Below is a snippet from the rawlog (names and other identifiers redacted).
>>  The offending sequence is always in the References headers section, and you
>> can see the line breaks there that show this.  So it sounds like this can't
>> be an issue with Dovecot, am I right?
> 
> Yeah, sounds like Outlook breaks with huge headers. That's one huge
> References header you have.

Summarising mail standards (WRT headers)

There is a limit of 4096 characters per line.

If Outlook is breaking at less than that it's a bug.

If the References: line is longer than that then it should have been 
truncated by the sending MUA - there's no provision for multiline 
References headers (which are a non-standardised import from Usenet anyway).