Has your Yosemite Mail.app been misbehaving? After upgrading to Yosemite have you had trouble sending and receiving email?
We’ve had reports of trouble with email from customers after upgrading to Mac OS X Yosemite (10.10). We here at MacHighway do believe that Apple gets a lot of things right, far more often then those other guys, and that’s why I’ve been Mac fanatic for 30 years (and an Apple user for 35). However, Apple does get some things wrong, in this case the latest changes to Mail.app in Yosemite may cause you trouble when trying to send and receive email because Mail.app will randomly replace your settings with what it assumes to be correct (Yikes!)
The best guide we’ve seen to solve this issue is at tedhagos.com. Ted has written a great article on fixing this issue, including a more detailed plist fix, if for some reason your settings still do not stick after. You can find it here.
To double-check you have the correct settings in your Mail.app, you can see what they should be on your cPanel. We have a knowledgbase article that tells you how called General Email Setup Instructions, here.
Our new cPanel upgrade also has a handy application you can download from your cPanel that will automatically configure many email clients, including Mail.app in Yosemite. That information, in the section of our knowledgebase called “Setting Up your Email Application“.