Tried all the solutions for hours!
But this is the way to fix it,
login to webmail of AOL,
then go to your account info,
on right hand side the last option:
Manage App Password
choose the last option: other app, type: windows mail
generate the password and copy it, then go back to your windows 10 mail App,
click on the account, now enter the password you just copied to the password field which just pop up.