Mailboxes are empty after upgrade to 10.5.6

Question

I just upgraded from Tiger 10.4.11 to Leopard 10.5.6, and after the installation the Mac has rebooted into the new OS. That was just a few minutes ago, and looking things over, all appears to be as before, and the applications launch and work, except for Mail.
In Mail, all my mailboxes are there, but there is nothing in them. Furthermore, I sent myself a test message, and Mail does not bring it in. Nor is the sent message shown in the Sent mailbox.
Can anyone tell me what is going on here? Where are all the stored messages that are supposed to be in my mailboxes, and why am I no longer able to send or receive messages?
Any help most appreciated.
Tom

Answer 1

I've encountered this problem on the last three upgrades from Tiger (10.4.11) to Leopard (10.5.6). I've done three different upgrade paths (simple upgrade, clean install, erase/install and migrate) and in all three cases, the Mail problem is exactly the same. When Mail launches, it says the Mail files need to be updated (or something similar), I say OK, and after a few minutes it reports that Mail is ready to use, I say OK and mail opens to a few generic mailboxes with nothing in them. All the mail seems to be gone. Mail hangs and I have to force quit. I can't send or receive mail.
Here is what I have learned and what I recommend. If you are reading this after you've encountered the problem, described skip to step 3. If you haven't yet done the upgrade start at the beginning.
By way of preview for the steps below; basically, you will document your current settings, then create a new, empty mail system. Then you will import your mail and reconstruct your mailbox structure. The steps below will guide you through this process.
1. Before you upgrade, document all of your email settings for login and password, server settings for sending and receiving mail. Also document the arrangement of all of your mailboxes. I recommend making screenshots (cmd-shift-4 followed by spacebar then mouse-click to capture an image of the window). Do this for all relevant views of your mailboxes, so you can see what you want your mailbox structure to look like after you are done. The pictures will probably land on your desktop and be named Picture 1, Picture 2 etc.
2. Upgrade your OS normally, do all of your software updates etc, but DON'T LAUNCH MAIL YET!
3. If Mail is running, make it stop. Trash the file; /Users/(yourusername here)/Library/Preferences/com.apple.mail.plist
4. Move the folder; /Users/(yourusername here)/Library/Mail to the desktop. This is where all of your email is. DO NOT TRASH THIS FOLDER!
5. Take the computer off the network. You don't want it to check your mail just yet. Either turn off your Airport, or disconnect your Ethernet cable, or both.
6. Launch Mail. It will ask you to configure it for the first time. Since it is not on the network, you will need to configure it manually, using the settings you documented in step 1. Don't let it configure itself, because it is not on the network and will not be able to find any servers.
7. After mail is configured, you can bring the machine back onto the network and confirm that your mail settings work. Undo whatever you did in Step 5.
8. Import your old mail into the new mail settings by choosing File>Import Mailboxes. Point the import step to the Mail folder on your desktop that you moved in step 4. NOTE: If you open the Activity Viewer under the Window menu > Activity, it will let you watch the subsequent processes, which can take a long time under some circumstances. Especially if you have a lot of mail, or if you are on a slow computer.
9. After the mail is imported, it will be in a folder called something like Imported Mail.
10. Recreate your original mailbox structure by dragging the mail files (you can select multiple messages) from the folder in the imported mail to the place you want it, or originally had it. This is where the screenshots from Step 1 comes in handy. Drag mail from your imported inbox to the new inbox, etc.
Some mailboxes will not exist yet. If you don't have a "drafts" folder, for example, create a new message (to anyone - it doesn't even have to be a real address) and save it as a draft. This will create a drafts mailbox and you can then drag mail from your imported drafts to the newly created drafts mailbox. If there is no Trash mailbox, create a new message and then delete it, this will create a Trash mailbox. You can create some of the mailboxes from the Mailbox menu > Go To and choose the mailbox you want. For example, to create the trash folder. Go to Mailboxes->Go To->Trash (or command-5) and that will create a trash folder.
You may need to recreate your rules/filters. You are on your own there. Maybe document them in step 1 along with the other documentation you make of your previous setup.
This is a big problem for a lot of people. I've seen it enough to have figured it out and I documented the steps for fixing it. I hope this helps.