"Undelivered Mail Returned to Sender" Error

"Undelivered Mail Returned to Sender" Error

Hi,

How do I rectify the following errors?

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. 


pitch@rafters.asia INVALID_ADDRESS, ERROR_CODE :550, ERROR_CODE :Verification failed for

<keenmeng.lew@erfocus.com>

No Such User Here

Sender verify failed



Best regards,

km