CiviMail's test email functionality does not check to see if a contact is deleted before using it for token substitution

When sending a test email to a email address, CiviCRM 'randomly chooses'? a contact from the database with a matching email to do token substitution.

This would be fine, however, it does not check to see whether the contact is deleted before choosing a contact.

This is a pain in particular when testing out checksums because it will try and authenticate against a deleted contact and this can cause errors.