Incorrect email address format
Issue
You run a DocGen Package and see this message:
An email address supplied in the {'To','CC','BCC'} field is not in correct format: {email address} (ResourceInvalid)
Cause
You could get this message when an email address on a delivery option is not in the correct format. The email address might have a typo or you may be using a tag to merge an email address into the delivery option, but that tag might not be pulling the correct data from Salesforce.
Resolution
Examine all the email address associated with any delivery options on the DocGen Package. Use the filed tagger and its Lookup Object functionality to retrieve the record you're using to generate documents. If the delivery option is using a tag to merge an email address, make sure that tag resolves to a valid email address. For more information, see Field Tagger.