Solution :
Please note that the above error will occur due to the below reasons.
1. The destination Email ID or domain name does not exist
2. The Email ID or Domain name might be misspelled
3. The destination Email ID Might be present in the localdomains.
We found that the domain is present default in the local domains of our server , but the MX record is pointed to some other server.
Due to this the mail servers will check with local domains only.
Kindly raise one ticket in your members area to diable the mail domain from our server.