Double-check them and try again” when you try to add a new account, the Mail app may be trying to join two accounts instead of setting one as a delegate. See Use aliases to add email addresses to your account for more info.
The Mail app will try to determine your email account settings.If the Mail app can’t locate your account, you’ll get the message "We couldn't find info for that account.Make sure that the email address is correct and then try again." After three unsuccessful attempts to connect to the account, you can select Advanced to add the account info manually.First, make sure you have the latest updates installed for the Mail app, Windows, and Surface.Windows Store apps are updated periodically by their publishers, and the updates will download and install automatically as they become available.
To check for app updates manually: If you uninstalled the Mail app, you can reinstall it from the Windows Store.
For info on how to install apps, see Install and uninstall apps on Surface.
For more help, see Find all your apps and programs.
If you remove the account you used to set up Mail, you’ll remove all of your accounts from Mail, Calendar, and People.
Instead of deleting your account, you may want to stop syncing email from the account.
If you see the error message “That email address or password didn’t work.