Norton is stopping my emails from being sent from outlook

I get the rejection message :  "554 5.7.1 End of data rejected: user not permitted to relay" - Does anybody know how I solve this?>

Hi Lennoxcoutts,

 

Norton displays the SMTP error codes that your ISP returns when a message is undeliverable.  Norton is not blocking the sending of your messages, but is simply relaying the notification from your ISP about the delivery failure.  You should check with your email service provider to see what the problem might be.  This sounds like you might be using an account that is not authorized by your ISP for sending, or perhaps you are using an incorrect port.

Thanks

I'll look into it.