On 4.10.2010, at 19.53, Tom Hendrikx wrote:
>> It seems Mail.app uses the timestamp ('arrived date'?) on the mail file
>> itself (Maildir here) to display the time.
>>
> When your MUA accesses the mail over IMAP, it does not see the Maildir
> file's mtime. Your MUA should use the Date header in the e-mail, or the
> date/time when it first sees the message (f.i. when not Date header is
> available).
IMAP protocol has a concept of "INTERNALDATE", which contains the time when the
message was received. With Maildir it's the same as the file's mtime.
With Mail.app you can configure it to show/sort messages by "Date Received"
(=INTERNALDATE) or "Date Sent" (=Date: header). I prefer the "Date Received" so
that a bad Date: header won't put the mail in the middle of the mailbox.
