Possible solution for not being able to receive emails

Question

I had a problem that's plagued me since Leopard was released a week ago. I couldn't receive all my emails on any POP boxes, and kept getting duplicates showing up of those emails it had managed to download.
I had 45 emails waiting to download, and it kept stopping on message 33. There was nothing different about that message, and I removed it via webmail instead. Still, Mail would not download the messages that remained.
The whilry progress circle would appear by four of the POP boxes but would never disappear, and I had to Force Quit Mail.
I had installed Leopard as an Archive & Install and preserved my users & network settings. I found that Mail had trashed my email servers list!
SOLUTION: Preferences > Accounts. Click on each account and edit the server list (the server dropdown has "Edit Server List..." in it.). Make the changes necessary for ONLY that account's servers, Don't change any others in the server list. Close the sheet, and choose a different account. You'll be asked to save the changes, do so. Now, edit the server for another account and continue until they're all done.
It looks like Mail isn't storing changes to every server that you change in the list, so when you do one of them, if you change another it loses changes you've made.
I still can't send emails though, but that's a separate problem...

Answer 1

Yes, they showed up in my Sent folder. What I did was send the same email to the other two addresses. I wrote a test email in account A, and addressed and sent it to account B & C. Then did the same from B to A & C, and from C to A & B. When all was said and done, I had 4 emails in my Mac.com inbox, and 1 email in each of my POP accounts. Since my last post, I tried taking my mac.com account offline, and tried sending an email from each POP account to the other, and they both got them.
No, I can't get to either of my POP accounts online.
The passwords are all correct, and unchanged. If there's an issue with them and OS X, it's a new one.
What's really bugging me is the amount of emails I'm NOT getting. I am not aware of any specifically, at least since the bouncing stopped. But, for example, I normally would have received about 90-100 emails in the past 9 hours, with around 40 of them going to my Junk box. While my Junk box has received close to 40 emails tonight, like normal, my inbox has only received 7, and 3 of those were notices telling me you replied to this post, and another was a confirmation email when I ordered dinner from Dominos. That's been the pace since about mid-day yesterday. Prior to that, I received zero emails in all accounts for the roughly 16 hours following my Leopard install. In fact, when I went to Mac.com to see if my missing mail was there, the last one there was time-stamped about 10 minutes before I did the install. In other words, whatever it was that caused this also kept my email from the mac.com website.
Confused yet?