Mail, MobileMe: Accessing your email account on different computers, keeping messages "in sync"

Changing a POP account to IMAP or Exchange

If your account type is POP and you have the option of using IMAP instead (check with your email provider if you're not sure), a good way to keep your messages "in sync" on different computers is to simply use an IMAP or Exchange version of your account in Mac OS X Mail. You can then disable the POP version of the account.

Note: It's important to back up any data that you wish to keep. Not backing up your data properly, or not following these instructions, may result in data loss. Proceed with caution and at your own risk. For more information about backing up, see this article. After backing up your data, verify that the data is properly backed up.

Changing your Mail settings

1. From the Mail menu, choose Preferences.
2. Select your current POP account. Make note of your incoming and outgoing mail server names, and user name.
3. Click the "+" button (save if prompted) and create an IMAP or Exchange account (in addition to your POP account); your server names may be different than the ones your POP account used. Optionally, close preferences and save your changes, then send a test email to yourself via the IMAP account. If this works, proceed to the next step. If not, verify your IMAP/Exchange account settings with your ISP.
4. In Mail Preferences, click the Accounts tab and highlight the original POP account.
5. Click Advanced.
6. Deselect "Enable this account" to disable the POP account.
7. Deselect "Include when automatically checking for new mail."
8. Close the Preferences window.
9. Quit Mail.
10. Repeat the above steps on the other computer if necessary.
11. Open Mail on each computer and access your IMAP account. You can watch Activity Viewer to monitor progress.

After that, any messages that appear on one computer should appear on the other(s). You can also choose Synchronize All Accounts from the Mail's Mailbox menu.

Using POP only

If your email account uses POP and you cannot use MobileMe, IMAP, or Exchange, you should configure the account so that messages aren't deleted immediately when retrieved from the server--set it so that messages are deleted after a few days, perhaps. See Viewing messages on multiple computers.