Installed El Capitan. Mail will not open. When I force quit and try to reopen a window opens stating the last time you opened Mail it was force quit while reopening windows. Do you want to try to re-open its windows again? Still does not open.

Hello Steve,

Thanks for using Apple Support Communities.

If Mail is quitting unexpectedly on you, then I first suggest to open the Mail app while holding the Shift key on your keyboard. This will prevent any messages from being opened during the initial launch.

If Mail unexpectedly quits when viewing certain messages - Apple Support

If the issue persists, then the next step I suggest is to start isolating where this is happening. You can do this by first booting into Safe Mode. If the issue persists in Safe Mode, then you can create a test user on your computer, and trying to use Mail there. More information on Safe Mode and creating a test user can be found in the link below.

How to test an issue in another user account on your Mac - Apple Support

If you continue to experience this issue, then please let us know.

Take care.

This sounds exactly like the problem that we're having. We spent a lot of time trying to understand where the problem was and finally found that disabling iCloud Drive "fixed" the problem. Obviously, this is NOT a fix, but we can at least get to our Mail. Hopefully, someone can help us determine where we go from here.

Disabling Mail’s access to iCloud Drive (iCloud Drive/Options) is our fix for now. iCloud Drive is now available, as desired, for other Apps. So, we won’t be saving Mail attachments in iCloud Drive, but we can certainly live with that. This was a huge bug for us on all three of our Macs! That said, I’m seeing lots of little bugs in El Capitan; surprising given the Public Beta.

Try opening Mail with the shift key held down.

We fixed our mail problem, which sounded the same as yours, by turning off the mail option in iCloud Drive. Now, it opens every time and do not need to hold down the shift key. Just an FYI the holding down the shift key didn't work at all for us.

This mail problem is on all three of our Macs after upgrading to El Capitan. So we have it working now. Hopefully, they will get all these bugs fixed.

I have the same problem. Already tried the shift key fix, but nothing happened. I already tried disabling wi-fi and disabling all the accounts to open again, but nothing really happen. What's funny, in my case, is that nothing happens when I try to open mail. It doesn't open any windows. When I click on the Mail menu, it doesn't let me click on Preferences. The "Window" menu has no window to open. I just click on it, nothing happens and no windows opens. CPU doesn't run into 100% or anything like that. It seems it's stuck in something.

Any ideas?

I decided to do a radical thing that worked for me. I went to the ~/Library/Mail/V2/ folder and moved the folder MailData to MailData_old. Then I restarted Mail. It opened a window prompting to reindex all the e-mail I had. It took hours (I don't know how many hours it took because I went to sleep). Now, in the next day, all is working again.

Best,

Leo.

Just to close the loop on this for us...

Launching with shift-key provided no relief.

Deleting Mail folder and rebuilding database was always successful, but relaunching Mail resulted in hang/spinning new beach ball which we let go for hours on one occasion.

When open, after successfully rebuilding database, highlighting and rebuild of mail boxes also provided no relief.

There's no question that our problem is an issue of Mail accessing something in iCloud Drive.

There are still way too many Mail related errors reported in Console for my liking, but from a Use perspective, things are stable and working reliably.

How do I disable the iCloud drive? My mail keeps closing unexpectedly after being open about 30 seconds while trying to download new mail. I want to try your iCloud drive fix.

Thanks,

Tracy

> How do I disable the iCloud drive?

System Preferences/iCloud/iCloud Drive

You can disable iCloud Drive completely, or use Options at the right end of the line to disable access on an App by App basis. We use iCloud Drive enough that we don’t want it disabled completely. Disabling Mail’s access was enough for us.

Hope that helps!

This also fixed what was evidently the same problem on my laptop (MacBook Pro (Retina, 13-inch, Early 2015) running El Capitan 10.11.2. Mail wouldn't open, all I got was the Mail menu bar and a spinning beach ball. Disabling Mail in the iCloud Drive Preferences brought everything back. Except, of course, that the iCloud Drive for Mail remains disabled. Trying to rebuild the mailbox, restart, and then re-enable the iCloud Drive for Mail simply restored the original problem. So that's where this situation is at the moment. I can't think being without iCloud Drive is that big a deal for Mail, I'm just glad to have the app back.

this worked for me - it took awhile, but it worked. Thanks.🙂