Mail spinning, won't delete, "reading table of contents", etc. help?

Question

First off, forgive my un-tech-ness.
I recently went away and before I left I
set my Mail Prefs to disable "remove
copy from server" since I would be using
a different computer and didn't want to
risk losing any mail. Was able to retrieve my
mail remotely with no problem. However, when I
returned home, even though I immediately changed
the preferences back to remove the copies from the
server right away, each message left on the server was loaded into my inbox three or four times. Then the fun started - spinning ball, messages like "reading table of contents","copying 48 out of 50" "opening mailbox". I moved the duplicates to the trash and even deleted them from trash,but then I had to force quit so when I opened Mail the
next time, same problems with hanging up and duplicate
messages all still there. Oddly (maybe not, I don't know
enough to know what's odd-) I can receive and send mail with no problem. I have to force quit every time. I tried moving MessageRules.plist to Desktop as suggested in another post, but no luck.
Thanks for any help anyone out there can offer.

Answer 1

Not sure, but the mailbox appears to have become corrupt (maybe “overstuffed”, see below).
Verify/repair the startup disk (not just permissions), as described here:
The Repair functions of Disk Utility: what's it all about?
After having fixed all the filesystem issues, if any, and ensuring that there’s enough space available on the startup disk (a few GB, plus the space needed to make a copy of Inbox), try this:
1. Quit Mail if it’s running.
2. In the Finder, go to ~/Library/Mail/POP-username@mailserver/.
3. Locate INBOX.mbox and move it to the Desktop.
4. Open Mail. A new empty INBOX.mbox will automatically be created within the account folder, and this will allow you to continue using Mail normally while trying to solve the problem.
Although INBOX.mbox appears to be a file, it’s actually a special kind of folder (a package) that contains several files. Ctrl-click on INBOX.mbox and choose Show Package Contents from the contextual menu to see the files it contains. Of these files, mbox is the most important and is where all your messages are stored. What’s the size of that file? Depending on its size, you may or may not be able to directly import it back into Mail in the next step.
An Incoming_Mail file may also be present, in which case it might contain messages that Mail couldn’t transfer to mbox. Incoming_Mail is also a standard mbox file like mbox proper, just named differently, and can be imported back into Mail in the same way.
5. In Mail, do File > Import Mailboxes and follow the instructions to import the INBOX.mbox that’s on the Desktop. I’m not sure what the import options available in Mail 1.x are, but you should choose Other / Standard mbox or something like that, so that Mail looks at the mbox file only (and Incoming_Mail, if present) and ignores the other files in the package.
If Mail doesn’t let you select INBOX.mbox in step 5 because it’s a package instead of a plain folder, rename INBOX.mbox to just INBOX (i.e. remove the .mbox suffix) so that it becomes a normal folder, and try again. You cannot do this directly in the Finder because removing a suffix by normal means causes the Finder to hide the suffix instead of renaming the file. To remove the suffix from the name, you must do File > Get Info (⌘I) on the file and change the name there.
Do with the imported mail whatever you wish. You may move the messages anywhere you want and get rid of the imported mailboxes afterwards, but take a look at the following article first:
Overstuffed mailbox is unexpectedly empty
If all is well and you don’t miss anything, the files on the Desktop can be deleted, although you may want to keep them for a while, just in case.
Note: For those not familiarized with the ~/ notation, it refers to the user’s home folder (i.e. /Users/username). Hence, ~/Library is the Library folder within the user’s home folder (i.e. /Users/username/Library).