Unable to send email to iCloud mail

[cdawei]

This is the error message:

hangelog: Exception: Failed to load changelog: HTTP 404
ComposeScreen: failed to send: 
Exception: Failed to send: 422 
{"detail":"mx01.mail.icloud.com rejected the message (554): 5.7.1 [PDR1] Message rejected due to local policy.
Please visit https://support.apple.com/en-us/HT204137. Txn ID 369e1bd8-e22c-4bea-af01-befec1f451e7"}