How to recreate account.plist after the file has become corrupt

Question

I updated my system to Mavericks last week and ever since my computer has become dramtically slow. Especially Mail takes about 30 minutes to open. I have discovered that the fault is caused by my account.plist file as it is 24 MB which seems way to big. I have already deleted the file and then Mail opens well and fuctions normal.
However when I add my accounts again it creates new POP folders in the V2 folder instead of using the old existing ones and it starts downloading the emails that still remain on the server. I would like to keep keep all emails etc just the way they are already on the system but basically just recreate a fresh "account.plist" file. How can I do this without the issue that mail creates new folders but just uses the existing folders???
I also already tried the following:
- delete "account.plist"
- Add new account in Mail
- New folder is created in the V2 folder for that email address
- Copy the old mbox files for that account into the automatically new created  folder
The above seems to work but mail still starts downloading 200+ plus emails from the server.......
Any help how I can edit my account.plist file and delete unnessesary items there?? It seems that there is a lot of text in the file regarding my hotmail account and I expect that this is causing it to be so large. I have no idea though how to read this file and what I can delete and what not.....
At this moment I am pretty stuck and any help is welcome here.

Answer 1

These fixes have helped others, depending on the situation.  I don't see one addressing your particular problem but they won't hurt.
Have an up-to-date Time Machine or other backup before attempting any major software updates or rebuilds.
For more about backups:
Time Machine Basics: http://support.apple.com/kb/ht1427
Most commonly used backup methods: 
https://discussions.apple.com/docs/DOC-3045
Methodology to protect your data.  Backups vs. Archives.  Long-term data protection:
https://discussions.apple.com/docs/DOC-6031
Make sure your software is up to date.  Apple recently released a Mail update.
Apple > Software Update...
A general repair to fix odd behaviors in Mail is  Mailbox > Rebuild.
Try booting in Safe Mode.
          Boot and when you hear the bong hold down the Shift key.
          It will boot slowly.  Be patient.
          Login the the user account.
          Restart.
Another fix to try:
Shut down Mail.
Open the Finder. From the Finder menu bar click Go > Go to Folder
Copy and paste the following
~/Library/Mail/V2/MailData/
Click Go.
Move all "Envelope" files to your desktop.
Restart Mail and let it convert/reindex your mailboxes.
If this worked, Trash the Envelope files file that are on your desktop,
if not shut down Mail and put them back.
Another fix:
Shut down Mail.
Open the Finder. From the Finder menu bar click Go > Go to Folder
Copy and paste the following:
~/Library/Containers/com.apple.mail/Data/Library/Caches/com.apple.mail/Cache.db
Click Go.
Move the Cache.db file to the Trash.
Restart your Mac and try Mail.
You can try restoring mail from a Time Machine backup.
Hold down the Option key and in the Finder Go > Library
Enter Time Machine.
Select a date and time from when Mail was working.
Restore Mail.
Advice from another thread:  https://discussions.apple.com/message/23657222#23657222
If mailboxes are missing:
Linc Davis
Re: downloaded Mavericks and cannot find mailboxes, any ideas
Nov 3, 2013 9:24 PM (in response to always need hlep)
Quit Mail. Force quit if necessary.
Back up all data. That means you know you can restore the Mail database, no matter what happens.
Triple-click anywhere in the line below on this page to select it:
~/Library/Mail/V2/MailData/Envelope Index
Copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select
Go ▹ Go to Folder
from the menu bar. Paste into the box that opens (command-V), then press return.
A Finder window will open with a file selected. Move the selected file to the Desktop, leaving the window open. Other files in the folder may have names that begin with "Envelope Index". Move those files, if any, to the Trash.
Log out and log back in. Relaunch Mail. It should prompt you to re-import your messages. You may get a warning that the index is damaged and that Mail has to quit. Click OK.
Test. If Mail now works as expected, you can delete the file you moved to the Desktop. Otherwise, post your results.