Emails Bouncing Back to Sender

Emails Bouncing Back to Sender

I had one person tell me today that when they try to send me an email it is bounced back to them. My email is hosted on Zoho. I am receiving some emails, but apparently there are others I am not. I had them forward the bounced email and error message to my personal email so I could tryou to figure out why.

Here is the message they are getting when trying to send me an email:

This is a delivery failure notification message indicating that
an email you addressed to email address :
-- s***y@g*********x.com
could not be delivered. The problem appears to be :

-- Recipient server unavailable or busy

Additional information follows :
-- Connection refused

This condition occurred after 30 attempt(s) to deliver over
a period of 92 hour(s).

If you sent the email to multiple recipients, you will receive one
of these messages for each one which failed delivery, otherwise
they have been sent.

Based on this error, it seems that there is a problem with the Zoho email server not responding. I'm kinda pissed-off at the moment, considering it may have cost me a $70K deal.