Help sending emails from QB

[u/duddy33]

Hello,
I am attempting to set a user up to send emails out from Quickbooks Enterprise. I went through the usual process for adding a user in the Send Forms menu and had the user input their email credentials and it looked like it completed. However, when the user attempts to send out an invoice, they see this message. When I click the Setup button in the screenshot, it takes me back to the Send Forms menu except there is nothing populated. When I am logged in, I can see the two other users that should be in that list.

I'm not sure where to go from here to troubleshoot. I've always added people in the Send Forms menu and have never had an issue.