Configure routing not working

I’ve searched the support forum but did not find anything related.

I can’t share the url because it’s from a secured intranet.

I did the configure routing on a few forms, but there is one form that it won’t work on. The error message is “WordPress was unable to send the notification email. Cannot send email because the TO address is invalid.”

But the emails in the TO are correct, and comparatively to other forms, everything is the same. The only difference is that this particular form has two different fields that it uses for routing. One field is Department, which goes to the applicable manager, and the other is Cost, which if it is over x amount or under x amount, goes to a different person.

I tried taking the Cost field off, but it still didn’t work.

For the life of me, I cannot figure this out…any help is greatly appreciated.