cannot sendmessage using the server iCloud
I am unable to send emails from my iCloud account. I keep getting the following error message:
Cannot send message using the server iCloud.
The sender address was rejected by the server.
The server response was: Authentication required prior to MAIL/SAML/SEND/SOML
Select a different outgoing mail server from the list below or click Try Later to leave the message in your Outbox until it can be sent.
It has been like this for more than two days. Can someone help me please?
[Personal Information Edited by Host]MacBook Air (13-inch, Early 2014), iOS 12.0.1