Incoming Mails are bouncing with 5.1.0- Unknown address error 550 - 'sorrt, no mailbox here by that name (#5.1.1).

Incoming Mails are bouncing with 5.1.0- Unknown address error 550 - 'sorrt, no mailbox here by that name (#5.1.1).

Dear Support team,

Incoming Mails are bouncing to  info@netgenesis.co.in with 5.1.0- Unknown address error 550 - 'sorrt, no mailbox here by that name (#5.1.1).

Please find the below snapshot of the mail.

   -------- Original message --------
From: Mail Delivery System < MAILER-DAEMON@ironport.opentransfer.com>
Date: 30/10/2017 12:50 p.m. (GMT+05:30)
To: Mail Delivery System < MAILER-DAEMON@ironport.opentransfer.com>
Subject: Undeliverable: Mitel's India contact

-------- Original message --------
From: Mail Delivery System < MAILER-DAEMON@ironport.opentransfer.com>
Date: 30/10/2017 12:50 p.m. (GMT+05:30)
To: Mail Delivery System < MAILER-DAEMON@ironport.opentransfer.com>
Subject: Undeliverable: Mitel's India contact

The following message to < info@netgenesis.co.in> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'sorry, no mailbox here by that name (#5.1.1)'

Please provide solution for the same.

Regards
Vijay Gupta
Netgenesis Technologies Pvt Ltd
Mobile : 8583095450