[Dovecot] SORT(DATE) and missing Date headers

[Rich at Whidbey Telecom]

We recently encountered this with a new VOIP voicemail system.  However, 
using Thunderbird at least, the time the message file was written is 
used (probably using "INTERNALDATE").

This might only apply if you're using Maildir's, but it shows that the 
behavior you're seeing might be specific to Mutt.

Rich

Kyle Wheeler wrote:
> Hello,
> 
> Occasionally, I get mail that's missing a Date header. The usual 
> suspects are iTunes weekly mailings and NYTimes email-to-a-friend 
> articles. I use qmail, which doesn't "fix" these malformed emails by 
> adding a Date header (like Sendmail does), so when they get to my 
> mailbox, they're just as badly formed as they were when they were sent, 
> which is to say, they have no Date header. Unfortunately, this means 
> that SORT (DATE) puts them at the beginning of the list---and in a 
> mailbox with lots of old mail, that's usually the wrong spot.
> 
> Now, my email clients will do some basic guesswork about when the 
> message was sent, usually by falling back on the timestamp of the 
> first-added Received header. So, they will display a date. But they have 
> to then sort all messages themselves in order to get a valid sorting. 
> Would it be possible to get Dovecot to fall back to Received header 
> parsing whenever a message is missing a Date header? The idea is that 
> SORT (DATE) would then become useful even in the face of commonly 
> malformed email. How hard would this be to hack into the current Dovecot 
> source? Does this maybe exist already (e.g. as SORT (X-DATE)?
> 
> ~Kyle