Why can't I add a new sender email address to the autoresponder email?

I am trying to change an email address for our auto-responder, but when I go to add it, it says it's already verified. Fine, but then when I go to select it from the drop-down menu, it's not an option. Any ideas?

I can see admission@ email there. Would you mind checking again? You can delete the email through your Settings page https://www.jotform.com/myaccount/settings.