Mail App Won't Start (OSX 10.10 Yosemite) I recently purchased a new Macbook Pro Retina (15-inch, Mid 2014). I installed a few normal programs (DropBox, 1Password, etc.). I did not open the Mail app at all. I then upgraded to Yosemite. After a seemingly successful upgrade, when I tried to open Mail for the first time, it hung without displaying any screens (though the menu bar does display). Leaving it for several minutes has no effect. Clicking anywhere transfers focus to a new application, causing the Mail menu bar to disappear. Clicking on the Mail icon again has no effect. Activity Monitor shows "Mail (No Responding". It uses no CPU and little memory (13.1 MB). Nothing obviously mail related (to me) appears in the System Log Console.

As part of troubleshooting, as recommended on a MacIssues.com article, I removed the Mail app Container (Macintosh HD ▸ Users ▸ rileymajor ▸ Library ▸ Containers). It rebuilt it on the next launch, but it seemed to have no effect.

How can I make my Mail app work, preferably without reinstalling the OS or other similarly drastic measures?

I have not configured any mail settings and have no saved mail to worry about. I just need it to run.

I have 4 Internet Accounts configured:


iCloud

Photos
Contacts
Calendars
Reminders
Safari
Find My Mac

Google

Contacts
Calendars

Twitter
LinkedIn (Contacts not selected)


I have no mail configured.
Try linking/adding a mail account to your Mac through System Preferences -> Internet Accounts. See if that fixes it.

(Which of course, it did. Might as well get the rep for it ;D )