Can send mail but not receive -- connection doctor OK, GetInfo shows msgs

Question

In the last couple of days I stopped receiving email on my Mac in the Mail app, but not my PC. Both access POP3 accounts at the same ISP, different POP3 accounts. All software is patched to latest version using Software Update -- PowerMac G5 Dual, latest OSX version. On the Mac, connection doctor says I'm A-OK (internet connection, POP connection, SMTP connection.) Also, if I do a Get Info on the inbox and show messages on the server, it shows 75 messages on the server. I have not retrieved messages to my knowledge (so I don't think the server thinks I already downloaded them), and the "Messages that have been downloaded to my Mac" pulldown option in Get Info confirms this, by not showing any of the 75 messages in the Show all messages pulldown option. But -- Get Mail does nothing! I have tried rebooting, deleting and recreating the account, etc. Since I can get POP mail for another account at the same ISP on my PC, and I have touched nothing on the Mac, and all the diagnostics show the connection and POP3 chat is working perfectly, this very strange. I do not think I have applied any patches or anything that might screw it up, but who knows.
The only strange thing that might be a clue is the little spinning status indicator next to the InBox label runs for about 30 sec or so before it decides not to do anything -- seems a little long. Any suggestions? Any way to do detailed debugging of the POP3 session to see if the Mac-server conversation is wanked up somehow?
Thanks!
David

Answer 1

For POP accounts, Mail uses a file within the account folder to keep track of which messages have already been downloaded. Deleting it should cause Mail to download everything still on the server as if new. I don't think it'll work in your case, but try it anyway just to be sure:
1. Quit Mail.
2. In the Finder, go to ~/Library/Mail/POP-username@mailserver/.
3. Locate one or two files named MessageUidsAlreadyDownloaded and move them to the Trash. Mail 1.x used MessageUidsAlreadyDownloaded to keep track of which messages had already been downloaded. Mail 2.x uses MessageUidsAlreadyDownloaded2 for the same purpose.
You can use the Account Info window first to remove from the server any messages you don't want to be downloaded again.
You may try creating a new user account in System Preferences > Accounts, set up mail anew there, and see whether the problem happens there as well.
Another thing you may try is using a different method to connect to Internet, if possible. Also, if Preferences > Check for new mail is set to Every minute, changing it to something greater (e.g. Every 5 minutes) might help.
Something that usually works is removing some messages from the server (download them with another mail client first, to avoid losing them). Sometimes, Mail chokes on a message it cannot download, and that prevents it from downloading the rest as well.
Any way to do detailed debugging of the POP3 session to
see if the Mac-server conversation is wanked up somehow?
Detailed debugging no, but looking at the Console could be informative:
1. Open /Applications/Utilities/Console.
2. From the File menu, choose either Open Console Log, or Open System Log, or both, so that the Console application displays the contents of both system.log and console.log.
3. Try to reproduce the problem and look at the bottom of the Console windows for messages that might be written there as a result. They may provide some clues as to what the problem is.