Rejected By The Recipient Domain 550 550 5.1.1 User Unknown: (state 14)

After I create the Hosting Account I create the email.
Then I try to send mail to gmail it is successfully.
But While I reply to that Mail I got the Following Error message.

From:Mail Delivery Subsystem mailer-daemon@googlemail.com

Technical details of permanent failure:

Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error.The error that the other server returned was: 550 550 5.1.1 User unknown: test123@onemg.in (state 14).

How to Resolve the Problem

Error message Clearly Says
1)User unknown After create the account it is difficult to find the user.Allow 30 minutes to one Hours Then try it your Problem Has been Resolve
2)Otherwise these email account is disable in there hosting account
3)Else this email is not present in there hosting account.


Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 5.1.1 User unknown: test123@onemg.in (state 14)