ICLOUD.com email not sending from iCloud.com or from iPhone.

For 7 months now. When I log into iCloud.com and try and send an email I get an error message saying "THIS MESSAGE CANNOT BE SENT AT THIS TIME. PLEASE TRY AGAIN LATER". Also, I cannot send mail from my mail app on my iPhone. I've contacted apple support case no. 10************, and they have ghosted me, they don't know what's going on.

The fact this is happening at server level, would suggest a problem with my account. This problem is causing me big issues that I'm not able to send mail.

On my MacBook, it just says outgoing server (offline).

The only way I can send mail is if I use an app specific password. However, I cannot add an app specific password for mail app on my iPhone as the server settings are automatically put in when you use an iCloud service.

Any help from anyone greatly appreciated.

[Edited by Moderator]