Mail continually re-downloading emails, and some mails have incorrect dates

Question

I've been having this issue for a few weeks now. This is only happening on my .Mac account (I have other IMAP accts and they work fine).
Every so often, Mail decides to re-download all of my emails. And recently, mail completely bugged out and changed the sent date of large portion of my old sent emails to the 23rd of April. So now emails that I sent a long time ago, are all showing up as being sent this week!
I've tried rebuilding the mailbox etc. No change. Any ideas?
Thanks.

Answer 1

I used to find this happening with older version of OSX after I did my usual 6 month clean, wipe, re-install and resume.
It's possible that the file which keeps a track of message downloaded from the server is corrupt. Goto ~/Library/Mail where "~" is your home folder and then delete these files
Envelope Index
LSMMap2
DefaultCounts
Next goto each account ".mbox"
This is in ~/Library/Mail then a folder which contains your email address example "Mac-steve.jobs"
inside there should be a folder list something similar to this:
Junk.imapmbox
Sent Messages.imapmbox
INBOX.imapmbox
Drafts.imapmbox
Deleted Messages.imapmbox
Inside each of them is a folder, called "Messages" and also some files, delete the files but not the "Messages" folder.
When you reopen Mail it will be as if you opened it for the first time. See if the emails come in, if they do then it's more likely to be a setting in Mail or even possibly something that's happening at the remote email server.
In Mail Right or Control Click in the left hand panel and select "Get Info" a box will come up with a drop down selection at the top showing active email accounts, select the one you are having problems with, either a list of folders will come up or a big long list of email messages, depending on how many you have will depend on how long it takes for the list to update. Once it has, select all the emails and Select "Remove From Server" this will delete them all from the server so at least when you re-open Mail they don't all come in again.
Hope something in here helps
Mark