Not able to receive mail, but able to send mail

Not able to receive mail, but able to send mail

Hello,

I am not able to receive mail from following is the bounce mail detail
< amiruddin.shaikh@quadrabay.com >:
68.178.213.203  Mailbox not found
Remote host said: 550 5.1.1 < amiruddin.shaikh@quadrabay.com > recipient not found.  < http://x.co/irbounce >
?

I have check through third party  https://mxtoolbox.com/ am able to see MX configure to zoho mail as in attached screen shot.

All the users in this are having same problem. Can you please look in to this ASAP. its urgent.
Please reply me on amir786_shaikh[at]rediffmail[dot]com

Thanks 
Amir