Apple's Mail e-mail client that is included with OS X is widely used by Mac owners for managing their e-mail accounts, be they on Apple's MobileMe or iCloud services or from a third party like Google, Yahoo, or AOL. The program works well for the most part, but it does have some annoying quirks, with one being that it may regularly issue a warning requesting you to enter your e-mail account password.
The warning says the IMAP or POP server rejected the password, but when you enter your password again in the password field the server still rejects the password and continues to present the same warning message.
This may happen to only one or two accounts at a time, so while some servers cannot be accessed, others seem to work just fine, which indicates the issue is not a hard cutoff of Mail's networking capabilities or password and account management features.
Additionally, the problem seems to happen rather randomly; there doesn't appear to be a single factor like waking from sleep that spurs the issue.
Similar account-handling issues have happened to Mail in the past, but the rejection of passwords seems to be a bit more frequent for those who have upgraded to Lion. In addition to Apple Discussions threads on the problem, a number of MacFixIt readers have written in regarding this issue.
MacFixIt reader Eddie writes:
I have three Verizon accounts that Mail gets e-mails for. Mail continually asks me for a password for two of the three accounts. The dialog goes away for a little while and then comes back. I read somewhere that this problem could be solved by making sure that each of the Verizon accounts have unique passwords, but it didn't work.
We recently covered a related problem for people who upgraded to Apple's new iCloud service, but it appears the problem is not isolated to that service. Unfortunately there are no direct fixes for this problem, but there are some things you can do to potentially help or at least reduce frustration around it.
- Wait it out
In most cases the password rejection is a temporary communications problem between Mail and the remote server. As a result, entering passwords repeatedly will not help the issue and will likely only lead to the same error message showing. Therefore, when the error shows, just click cancel and set the server to be offline. Generally after 5 to 10 minutes you can click the tilde symbol next to the server in Mail's sidebar and the server will reconnect just fine.
- Remove Mail account keychain entries
Mail stores its passwords in the user's keychain, and if for some reason the keychain entry is not working properly then Mail may be sending an improper password to the server. Therefore, one approach you can take (especially if the problem happens very frequently) is to remove and reset the Mail entries. Open the Keychain Access application in your /Applications/Utilities/ folder, and then search for password entries for your e-mail account. It may be easier to isolate the password by searching for your account provider's name (such as "Gmail" or "Yahoo") and then removing the revealed password entries. Do not worry about removing the wrong ones, as your system will just replace them when you access the respective services.
After you have removed the passwords, relaunch Mail and enter your password again when prompted, making sure to click the option to save the password in your keychain.
- Remove the Mail preferences file
While you can try troubleshooting this problem by removing your Mail accounts and then setting each back up again, an easier route that also tackles other factors that may be contributing to this problem is to force a rebuild of Mail's preferences file. The preferences file is called "com.apple.Mail.plist" and is located in the /username/Library/Preferences/ directory. If you are using Lion then the user library will be hidden, but you can still access it by holding the Option key and then selecting Library from the Finder's Go menu.
After you have removed the preferences file, the program will not show any of your e-mail accounts when you launch it, but your mailbox organization for each account should remain intact and reappear when you add your account settings back to Mail.