Can't add email accounts to Apple Mail

This just happened to me, but I got it back! I deleted said account (one of my gmail accounts) from apple Mail. But it wouldn't let me add a new account. I clicked on the google link in accounts and just signed into my account that way. Lo and Behold it popped into my mail and my mail was back! Hope this helps anyone else.

Created a SiteGround email account. Tried to add the account to my HighSierra (10.13.1) desktop Mail app (thru System Preferences) without success. (Was able to add it to my Thunderbird app, tho.) Tried to add the account to my iPhone (iOS 11.4.1) and was successful. On the desktop, System Preferences > Internet Accounts claims that the email address and password are invalid. If iOS accepted that combo, why not MacOS?

I have a similar issue with former Gmail accounts IMAP'ed to Apple Mail. I was changing passwords for these accounts, formerly a simple issue, when a pop-up window informed me that "Google requires authentication via Safari." What? Why? I almost never use Safari, preferring Chrome, so what is this roundabout? Very crazy.

I have a similar issue with former Gmail accounts IMAP'ed to Apple Mail. I was changing passwords for these accounts, formerly a simple issue, when a pop-up window informed me that "Google requires authentication via Safari." What? Why? I almost never use Safari, preferring Chrome, so what is this roundabout? Very crazy.

They've really messed it up trying to make it foolproof for those "automatic" types that Mail offers to try to setup.

There's something that needs deleting about Mail, but not sure if it's in Containers, Caches, Preferences, or all of them. :(

the same happen to me, I stopped getting email in one of my gmail accounts and did everything I've found and nothing works.

so I deleted the gmail account and now can't add it back on.

every time I try I get this message. "Authentication Failed" Failed to authenticate with Google, please try again later.

so I try again later and get the same message. this is so frustrating!!!

it's just a bit frustrating, when I try to add my account I get the google pop up and opens safari, then it says that it failed.

then I go to the gmail account and check mail and open the security email they sent and I click that it's ok to allow and add my gmail email address but the same thing happens over and over.

this just sucks!!

Same here. It's ridiculous. One day, my Mac just stopped receiving my gmail. I get it thankfully, on my iPhone.

so. what is the deal. I deleted the account, and now it will not let me add it back. I go through the steps, click DONE and it does NOTHING.

I updated to High Sierra and all my outlook accounts stopped running. In desperation, I deleted them and when I went in to add them, I get to the screen where you have to select the options you want to sync (Mail, Contacts, Reminders, Notes) and when I click NEXT, the wheel spins briefly and then nothing happens. I cannot find a solution to this and have no idea what is going on.

I've had the same problem since upgrading to Mojave.

...And then it didn't work, anyway. What's going on with Apple Mail?

Same here as of this week. Can't add back an institutional gmail account. Stops dead at the "Done". I have tried a dozen different ways and nothing works. Aaaargh.

I have this same issue first my mother's iMac then my own I tried adding the same account on another machine no problem. I'd say either mail or internet accounts in sys preferences has a bug.

This is not a solution

Wow, great tip if it works, thanks! :)