Can I delete an old "account" from my e-mail program without losing mail?
With most e-mail programs, including Outlook, Outlook Express, Eudora, and Entourage, deleting an e-mail "account" in the program does not delete the messages that have already been retrieved. You can safely delete or replace an e-mail account in these programs without affecting or deleting previously downloaded messages.
However, the Mac OS X Mail, Windows Live Mail and Thunderbird programs work a little differently. Read the information below before deleting accounts in those programs.
Mac OS X Mail
With the Mac OS X Mail program, when a mailbox (account) is deleted, it removes all messages associated with that mailbox.
Before deleting a mailbox in Mac OS X Mail, first move the downloaded messages into another folder or to the Inbox. That way the messages will still be in your Mail program after you delete the mailbox.
Windows Live Mail
With Windows Live Mail, when a mailbox (account) is deleted, it removes all messages associated with that mailbox, similar to Mac OS X Mail.
Before deleting a mailbox in Windows Live Mail, first move the downloaded messages into another folder. That way the messages will still be in your Mail program after you delete the mailbox.
If you use Thunderbird and originally set up the account to use the "global mailbox", then it's okay to delete the account. However, if you set the account to save the messages into its own mailbox, then deleting the account will also delete the messages.
Recovering deleted mail accounts in Thunderbird
If you have accidentally deleted one of your mail accounts by clicking on the "Remove Account" button in Thunderbird, this does not mean that your mail has actually been deleted from your computer. That mail should still exist in a child folder in the Mail folder in your profile folder. (This assumes that the account is not using the Global Inbox, in which case its mail would be stored in Local Folders.)
Once you've gone to your profile folder and verified that the mail for the deleted account still exists, do the following to get it back into Thunderbird. You may wish to make a temporary backup of your profile folder before proceeding.
1. Start Thunderbird and create a new mail account, using the same email address and server settings as the account you deleted.
2. It will create a new account directory with a numeric suffix. For example, if your old mail account directory was pop.gmail.com it will create a pop-gmail-1.com. Use the browse button in Tools -> Account Settings -> Server Settings -> Local directory to specify the old account directory and restart Thunderbird.
3. Check the accounts inbox folder to see if it has messages. If not then you probably specified the wrong location and need to use the browse button again.
4. Its recommended you leave the account directory that you created in step one alone - it only wastes about 10KB due to several default files that Thunderbird created. However, you can delete it (after exiting Thunderbird) if it might cause confusion later on.
If for some reason this doesn't work you can import each folder using the ImportExportTools extension. Each folder is stored as a text file with the folders name and no file extension (a mbox file) in a directory named after the accounts mail server in the profile . For example, if you wanted to import the inbox folder for gmail you'd select the "Mail\pop.gmail.com\inbox." file. Ignore the inbox.msf and inbox.sbd files.