The undeliverable email detection feature is extremely useful for proof owners so they can immediately know if the reviewers they have invited to a proof did not receive the invitation email. Most often, the cause of this notification is a mis-typed email address, or their email inbox is full.
If you have received an undelivered email notification:
- Open the proof’s info pane and double-check the spelling of the email address of the reviewer.
- If the email address is incorrect, in the workflow step add the correct email address of the reviewer in the anyone else? field. Once you have added the reviewer, click the 3 dots icon next to the incorrect email address and remove the reviewer.
This article on adding and removing reviewers will be handy too.