CRM CLOUD BROADCAST - ERROR

Hello Community,

While trying out Broadcast feature - I ran into following error:- Please refer to the attachment:

1. S/MIME identity without logical name "DONOTREPLY@TPCUS.COM" does not exist.
2. Signing Error: S/MIME without logical name "DONOTREPLY@TPCUS.COM" does not exist.
3. Signing mail failed - no valid certification for sender address?

Please guide how to resolve the same.

Regards

Kumar