I was having this issue also, tried restarting the computer, editing the SMTP, nothing worked.
When I opened the Apple Mail app all my email accounts failed to connect. Found insideThe authors of this book are seasoned Mac and security professionals, having built many of the largest network infrastructures for Apple and spoken at both DEFCON and Black Hat on OS X security. View Apple's documentation on how to add an email account to your device. Hope this helps! We recently received queries on a quick fix to fix the issue from our readers. sometimes it just wont send, tell them to try again, and it works. If you're having issues with an iPhone or iPad email account that has already been set up, contact our GoDaddy Guides. If you cannot verify your account name or password in Mail app, try to type in the password to verify the account in System Preferences. If that doesn't fix the problem, try these steps and attempt to sign in after each one: 1. I know the password is correct and I can create other mail accounts with mail on the Mac.
Step 3: Then on the drop-down menu, click on System Preferences.
