Wrong date being used for some messages

[tanstaafl]

https://addons.thunderbird.net/en-US/th ... te/?src=ss claims "The “Date” column in the Thunderbird / SeaMonkey thread pane shows the date from the header of the email message, which is not necessarily an accurate indication of when you received it. The “Received” column is supposed to show when the message arrived in your mailbox, but it does not work properly for IMAP folders. It will if you install this add-on!"

What email provider are you using?

"Have I discovered another problem by turning on "Received" for the list option and finding NO difference from Date?"
Nope. Just means it was delivered within about a minute. I can get a small message I sent from my Fastmail account in my Gmail account in about 5 seconds.

I did some more searching for any mention of Delivery-date: headers and found https://bugzilla.mozilla.org/show_bug.cgi?id=612990 . It had an example where Orange.fr's servers used it. It states "If no Date: header, or if malformed/corrupted Date: header, Tb uses Epoc time(1970/01/01 GMT+0000) or current date(local time of download in "From -" line, if POP3)".

I stumbled across https://tools.ietf.org/html/rfc2076 which lets you search "Common Internet Message Headers". It does mention a Delivery-date: header - it seems to occur when a message is converted from X.400 standards to the RFC882/MIME standard (aka Internet email). "At one time, the designers of X.400 were expecting it to be the predominant form of email, but this role has been taken by the SMTP-based Internet e-mail. Despite this, it has been widely used within organizations and was a core part of Microsoft Exchange Server until 2006;"

[aajax]

Just came across a reason that this is even a bigger problem than previously thought. It seems that TB never establishes a permanent value for the date for these messages. A consequence of that is when messages get moved to a different folder, as happens when archiving, TB generates a new date to correspond with when that move occurred. Depending on when the move happens, as with archiving messages after they get pretty old, this has the affect of changing the date by years and of course, depending on how archives are handled, placing them in folders where they would never be findable.

Whatever, TB might decide to do for dates where there is some deficiency with the message header when it decides what value to use that value needs to become permanent. Asking the user what date they'd like, or how they like the ambiguity resolved to include allowing the user to enter/edit the value after the fact seem to be things that would be reasonable approaches where as the present scheme is very problematic.

[TheThiefMaster]

I had some emails like this from 2007 - they lack the "Date:" header and in fact the only date in the email source is an "x-apparently-to:" header (which shows the date that gmail uses) the emails originated in yahoo, and this header is apparently a yahoo thing, though gmail appears to read it.

Thunderbird, not supporting this header, instead sets the current date/time.