Remote SMTP server has rejected address

Hi!

My iCloud.com mail address cannot recieve any mail.

I can logon to iCloud.com using the apple id *****

Your message cannot be delivered to the following recipients:

Recipient address: ******

Reason: Remote SMTP server has rejected address

Diagnostic code: smtp;550 5.7.1 ******... unknown user

Remote system: dns;mail.orcon.net.nz (TCP|17.172.204.239|51103|219.88.242.10|25) (mail.orcon.net.nz ESMTP CanIt-Appliance)

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