mail loads then quits what should I do?

first quit your mail app. then go to your library and locate the folder below

~/Library/Containers/comapplemail/Data/Library/Logs/Mail. Delete all files located in this directory

relaunch your Mail app

Go to User/Library/Containers/com.apple.mail. Move the folder com.apple.mail to your desktop. You must move the entire folder, not just the contents.

Restart, re-launch Mail and test. If the problem is solved, recreate any required Mail settings and import any emails you want to save from the folder on the desktop. You can then put the folder in the Trash. If the problem remains, return the folder to where you got it replacing the one that is there.

If that doesn’t solve it repeat the above using Containers/com.apple.MailServiceAgent.

Information learned from Linc Davis.