To view or export your list of all undeliverables:

Select PoliteMail > Lists > Undeliverable

undeliverable

PoliteMail manages undeliverable email for you automatically.  It removes any undeliverable messages from your Inbox, places them into the Undeliverables folder (added to your Outlook Mail Folders, below the Inbox and Sent Items) and tracks any hard bounces (undeliverable error codes in the 500 range) as undeliverable.  Other returned messages, including soft bounces and delay messages, should not be considered undeliverable as the email will typically get through later.  Undeliverables are shown on your list using a gray box behind the PoliteMail contact icon to indicate the address was undeliverable on the last email sent.