Folder Contains no items no operation can be performed warning

I just bought Em Client after using it for some time and overall like it. I was able to add the first two gmail emails with no problem, but the last gmail email wasn’t taken. There is a triangle warning symbol next to it, and where email should be is the notice “this folder contains no items and no operationa can be performed.”
When I compare the data from the first two to this one I see that this one has an option for backing up sent items that the other two do not have otherwise they are all the same. This is an email of a juvenile user who needs an email for school correspondence. I am not sure if this makes a difference.

Can I just add that I am not a techie by nature as well?:confused:

Child accounts, if that is what it is, can’t be used in email applications. That is restriction from the provider.

They can only be accessed through a webmail interface using a web browser.

Gosh, I wish I had known that before I bought the app. The entire reason I bought the app was so I could easily see what was going on across all three emails. What a bummer. Thank you anyway.