Cannot receive emails

Cannot receive emails

I have set everything up and have the MX records pointing only to Zoho and nothing else. 

I am not reciving any error message when I send an email to the zoho email address but there is nothing in my Zoho Inbox. I have several zoho users on the domain and all of them can send but not receive emails and I need them to work asap.

Please help me and tell me what I need to change, thank you.