I'm just adding a bit more color to this thread, as I know the OP and he is actually requesting this for me.
The account was made in 2009, when you could create a google account using a non-gmail account. Joe, the OP, created a Google account using his work email.
Sometime in 2015, our company switched over to Google Apps, and Joe's email account became a google account. So, there is the google account with an email address of
j...@ourcompany.com, and now
j...@ourcompany.com, which is a google account.
It seems that this somehow wasn't an issue with Feedburner, as we have an email thread where an employee confirms the Feedburner credentials (using
j...@ourcompany.com and the old password) work on 5/23/2016.
My assumption is that since then, Feedburner started forcing logins with Gmail accounts, because we can not log in with the old credentials now.
Any help would be appreciated.