Sometimes, for some reason, Mail stops working. We don't usually know why. But, sometimes you can fix it with a couple of clicks. Here's how.
Quick Fix when Mac Mail doesn’t work
Fast and easy way to send a file by email on the Mac
There's always another way to do things-- sometimes a better way! Here's the easiest way to send a file via the Apple Mail app.
Put frequently used Mac Mail folders and Mailboxes into Favorites Bar for easy access
Put frequently-needed Mail folders into the favortites bar at the top of the Mail window. Quick and easy access. You'll use these a lot.
Add text labels to the Mac’s toolbars so you know what the buttons are for
Add text labels to toolbar buttons, making them easier to identify & easier to click on (because they're bigger). Works in Finder, Preview, Mail, and more.
Use Mac Mail’s Activity window and Connection Doctor to see what Mail is doing
If Mail seems stuck, try going to the Window menu and choosing "Activity" and also "Connection Doctor." You'll learn a lot there.
Smaller Mac Mail mailboxes open more quickly
The Mac's Mail app opens smaller folders faster than fuller ones. Speed up your Inbox by moving old mail to other mailboxes. Makes a big difference.