Known Mail Bugs?

Question

1) I have Mail preferences set to retrieve new messages every 5 minutes.  But whenever I click on Get Mail, it seems to find several messages not yet retrieved and there is a progress bar showing the number of messages being retrieved. Also, these numbers seem to be daily totals such as "15 of 25", but I can find no explanation of exactly what those numbers mean.  My conclusion is that Mail is NOT getting new mail every five minutes, but waiting unitl i click on Get Mail  to query my mail servers.
2) Fairly often, when I click on a message header in my message list, all that displays in the message pane is the subject and details of the message but not the contents. I have to quit and restart Mail to get the proper behavior.
Are these known bugs?

Answer 1

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
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 folder window will open. Inside it there should be files with names as follows:
Envelope Index
ExternalUpdates.storedata
Move those files to the Desktop, leaving the window open. Other files in the folder may have longer names that begin as above. 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. Warning: The process may take hours if you have gigantic mailboxes. For reasonable-sized mailboxes, it should only take a few minutes.
Test. If Mail now works as expected, you can delete the files you moved to the Desktop. Otherwise, post your results.