Stock email app says "Server Password has changed", but it hasn't

[eblackwell]

I can't get email suddenly on my Samsung Galaxy S6 (Android version 6.0.1); starting yesterday morning, I get that error: "Server Password has changed", but it hasn't. Email worked fine ever since I got the phone and just popped up with the error with no changes made.

I double-checked the settings and they are correct.

The same email (and settings) works fine on my Samsung Galaxy Tab 4 in the stock app.

The same password works great on any PC too.

I spoke with the provider, but since the account works everywhere but the Samsung S6, they say the problem is with the phone.

Any ideas? TIA

 

[eblackwell]

I deleted the account on the advice of Xfinity tech support; now I can't add it again because it says bad password.