After upgrading to OS X Yosemite, you might find Apple’s Mail application may crash or hang when you open it, preventing you from accessing any new messages. This can be exceptionally frustrating to manage, especially when it persists after restarting your system. If mail is constantly quitting after upgrading, and especially if it quits immediately when you open it, then there are several approaches you can take to fix this situation.
Launch Mail in Safe Mode
When you open Mail, the program will show the last Mail message that you had selected, and if this message contains errors or corruption that is causing the crash, then this may trigger Mail to always crash when opened. To bypass this and have Mail not select any mailbox or message to show when launched, open the program and immediately hold down the Shift key until Mail is opened. If this causes the program to launch successfully, then you can investigate which messages or mailboxes are causing the issue.
Boot your Mac into Safe Mode to launch Mail
Another approach is to boot OS X itself into Safe Mode by restarting and holding the Shift key down immediately when you hear the boot chimes. This will only load essential features of the operating system, and while you should expect it to run noticeably slower in this mode, it may allow Mail to load properly when launched. If this occurs, then reboot normally and try Mail again.
OS X will save window locations and the open documents for most open programs, so if you quit the program these items will be restored when it is next launched. If after upgrading OS X there is some problem with how the prior saved state of Mail is being handled, then this could be the reason for Mail crashing. Therefore, try removing Mail’s saved state, and then re-launching Mail:
- Go to the Finder
- Hold the Option key and then select Library from the Go menu
- Go to the Containers > com.apple.mail > Data > Library > Saved Application State folder
- Locate and remove the folder called “com.apple.mail.savedState
- Re-launch Mail
Temporarily disable Mail accounts
Go to the Internet Accounts system preferences, and then uncheck the Mail option for each account you have listed there. When all are unchecked, open Mail to see if it will launch correctly. Then quit Mail, re-enable your Mail accounts in the System Preferences, and try opening the program again.
Uninstall or disable any third-party Mail add-ons
If you have any third-party programs that interface with Mail, then uninstall them. These can be password managers, or junk mail filters, content managers that will handle attachments, or security software for encrypting messages and connections. Sometimes these programs may simply not be updated to work with the new version of Mail, or may just be experiencing a temporary hiccup that will benefit from a reinstallation.
If you are uncertain if you have any such programs installed, then try going to the Library > Mail > Bundles folder and remove any items in it. There are libraries in OS X that have instances of this folder. The first is the global one at the root of your hard drive (Macintosh HD > Library), and the second one is the one in your user account, accessed by holding the Option key and choosing Library from the Go menu in the Finder.
Remove and rebuild Mail’s container
Mail is a sandboxed application in OS X, meaning that like many other applications it and its resources are isolated from other processes for security and stability reasons. As part of this setup, OS X will create a virtual container in which the program accesses the system resources it needs, and does so by accessing parts of the OS X filesystem through a special directory tree in your account’s library. This directory tree primarily contains aliases, but also contains files specifically for Mail, such as its preference and cache files.
If you remove the container for Mail, OS X will simply rebuild it and have Mail re-create the files it needs; however, doing so will clear out settings contained in these files, requiring you to set these up in Mail again. These can include mail accounts, signatures, smart mailboxes, and mail filters, so if you remove and rebuilt Mail’s container, expect to set these up again.
With this in mind, before clearing Mail’s container, be sure you have a full backup of your Mac. Then access the Go menu in the Finder with the Option key held down, and choose the menu item called “Library” that appears. In the Library folder, go to the Containers directory and move the folder called “com.apple.mail” to your Desktop (so you can restore it easily, if needed). After this, re-launch Mail, configure your e-mail accounts and other settings, and you should be up and running again.
Again, because of potential complications with setting up Mail, use this option after you have tried all others, after you have created a full backup, and only do so if you cannot get Mail to launch properly by any other means.
UPDATE (10/20/2014): Added information about removing Mail’s container as an option.