Unable to Send and Receive Emails on iCloud *******Urgent*********

Dear Apple Support,

I am experiencing issues with my iCloud email account. I am unable to send or receive emails, and I receive the following error messages:

• When I attempt to send an email, it is placed in my Outbox, and an error pops up stating: "The username or password for iCloud is incorrect."
• When others try to send emails to me, they receive an error saying: "Cannot Send Mail 's******@icloud.com' is not a valid email address and has been rejected by the server."
• In my iCloud Mail settings, I see the following indication: "AUTH_ERROR_INVALID_USR_TOKEN."

I have verified that my email address is correct, and I am using this iCloud email as my Apple ID.

Additionally, I have purchased iCloud+, but the issue persists. I have already tried basic troubleshooting steps, including checking my SMTP settings, updating my password, restarting my device, and verifying my iCloud account.

Could you please assist me in resolving this issue? I would appreciate any guidance on how to restore proper email functionality.

Thank you for your support.

Best regards,

Sachinthana