My mail keeps crashing every time I try to open it on my Mac.

Hello!

I had this same issue just a few days ago on my iMac running OS X El Capitan. The problem, for me at least, is that this older version of the Mac operating system isn't compatible modern email message(s) you may have in your Inbox. To fix this, I signed into my Mail provider's online mail interface (since I have iCloud mail, I went to https://www.icloud.com/), and I moved all my email in my Inbox into a new mailbox folder I titled "Older Message [Date Range]". This solved the problem for me.

If this doesn't work for you, or it isn't feasible, you could always use your Mail provider's online mail interface full-time instead of Apple Mail. If you do this, I'd recommend using Google Chrome, since it's the most up-to-date and latest supported browser for OS X El Capitan.

Jack

Apple Mail broke today. Started crashing at launch. Did something with Apple or Google Gmail change today?

Since I'm still in OS 10.11.6 bc of old Adobe apps, Apple Phone support won't help beyond telling me to launch mail with shift key down and confirming Connection Doctor is working. I managed to narrow it down to JUST my PERSONAL GMAIL mailbox with suffix @gmail.com. My other gmail accounts and mail work OK. So does iCloud and Earthlink. In case I had corrupt personal gmails in last 24 hours I deleted all of today's emails off the Google server.

Because Mail quits when I check my personal gmail "Mail" in Internet Accounts to turn that mailbox on, it doesn't show up not in my mailbox list so I can try rebuilding.

I'm afraid to delete it from my Internet Accounts and create a new one. I've had a lot of problems with keychain getting corrupted if I tinkered with internet account list. That broke all internet accounts (esp. Google Accounts). Only Apple Tech was able to fix Keychain after hours on phone. But I'm afraid to try that now, because they won't help until I upgrade my OS. But I don't want to upgrade until I get my main email working again.

Any Thoughts?