I have a simple list with one field I named ‘Recipient’. It is a name field that allows you to select other sharepoint users. The workflow has one action, send email that does a workflow lookup at the Recipient filed on the current item and returns the field as a semicolon delimited email address. When I create a new item and select myself as the recipient the email gets sent but if I select anyone else the workflow goes into suspend status with the following status:
Lisa,
A quick thought is that the workflow may not be assigning the email address for you correctly. Also the fact that your workflow is not filling in the test field means something in that logic is failing and could be causing your emails to fail.
Can you try adding a send to email step underneath your criteria step. Basically replicate that in the same stage and see if it works. Also put a stop after the email and use the test field before the stop.