Undeliverable: (message) .... 503 this mail server requires authentication when attempting to send to a non-local email address.

Undeliverable: (message) .... 503 this mail server requires authentication when attempting to send to a non-local email address.
This is to do with your email client not being configured properly. For a solution to this problem please click here and choose your desired email access, then follow through the instructions on how to set up an email account for that system.