Unable to receive an email.
Email sent from firstname.lastname@example.org to email@example.com was not delivered.
firstname.lastname@example.org received following message:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain example.com by external.mailserver.com [10.10.10.10].
email@example.com is not configured on external mail server.
Contact owner of external mail server regarding the issue or change external mail server to local one.