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:
I am having exactly the same problem as you described. None of the suggestions listed here fixed my problem. Did the suggestions fix yours? If not, did you ever resolve this?
I have a similar field in my list called Approver. When I specifically send the email to myself, it works, but if I send it to the Approver, the workflow gets suspended.
My list field is set up as Eric suggested. and If I display my Approver field, it is filled in and returns a valid email address.
Any other suggestions out there?