mail won't open in el capitan

Same problem

Same issue here. Did not happen in El Capitan GM build.

Does the mailbox need rebuilding from command line? If so, please advise.

Same problem -- deleted V2 files but no good. Pref files aren't it either.

Same problem. Mail launches. A few windows open, then it immediately crashes.

Have you received any answer? My email is stuck and I can not work.... I'd love to know if you found a solution, thanks

David Kadosh

I've spent HOURS on the phone with Apple Care; my "case" has been escalated to engineering - but there's no indication of when they will address it. Apple appears to be aware that problem is effecting lots of people, but they also appear to be treating on a case-by-case basis rather than acknowledging that it's a broad-based problem that has to be fixed. My recommendation is to call Apple Care and be insistent that they work with you until it's resolved!

GOT IT WORKING!!!

My VOODOO solution:

I was having the same problem and gave up and made a Genius Bar appointment. Then I decided to create a new user account and logged into that account and set up Mail in that account. Mail was working fine in the new account, so I knew I could at least use Mail, even if it meant logging into a different account. In the new account, I set up Mail as before with an iCloud account and an Exchange account and worked for a while. Upon logging out of the new account and back into my old account--(pause)--Mail worked perfectly fine. So, my simple solution is (in this order):

1) Threaten your computer with a trip to the Genius Bar (actually make the reservation to show it you're serious)

2) Create a new user account on your computer and completely set up mail on that account (I actually sent some mail in that account)

3) Log back in to your old account

4) Don't forget to cancel your Genius Bar reservation

(Some might think steps 1 and 4 are unnecessary.)

Here is a fix if you are a Time Warner Cable customer and have upgraded to El Capitan. Apparently TWC has changed their incoming and outgoing server address names and the old "pop-server" names are no longer recognized with El Capitan.This is why I was no longer able to receive emails when I upgraded.

1. Delete your email account on your MAC.

2. Sign out of iCloud.

3. Re-add your email account. The system will automatically change to the new server address "mail.twc.com"

4. Sign back in to iCloud.

5. Delete your email account on your iPhone, iPad and iPad mini as well. (This is why I was no longer able to receive emails from my phone. I kept getting the message "this email address is being used on another device" because of the "new" incoming server address on my MAC versus the "old" one on my phone.

6. Re-add your email on your iPhone and other devices. Again, the system will automatically change to the new incoming server address "mail.twc.com."

It took me 2 Apple Chats and hours on my own to figure this out. I hope this saves someone else some time.