I've got a form with multiple optional approvals - that part works. I then send an email to these people via  the Send Email function and add the fields as follows:

To o%Workflow Context:InitiatorUserId%]
CC C%Current Item:Amend_GenManager%] ]%Current Item:Amend_HRMgr%] ]%Current Item:Employee%] ]%Variable:vDeptApprover%]

Note, some are People fields, with one a string field.  That all works as long as they are either all unique or blank. But if I have a duplicate email across those fields (a valid occurrence within the data) I get the following in the workflow:

"WorkflowTerminatedException: Each email address in the personalization block should be unique between to: cc: and bcc. We found the first duplicate instance of {email address}"

Terminating a workflow due to a duplicated email address is a royal PITA! Any ideas on how to get around this, noting the mix of people/string fields?

Thanks.