Can't receive emails but can send after following all directions

Can't receive emails but can send after following all directions

I have changed the CNAME to point to zmverify.zoho.com and changed the MX records where my domain is hosted at GoDaddy. I made sure that ZOHO was the only MX records and made the values identical to the instructions. This was changed over 24 hours ago and still no incoming. Everything on this end looks good to me. What I get for an error code is:
[Return Code 550] sid: JiqH1o00g0C5F6001 :: 5.1.1 <fred@insurance-investments-services.com>... User unknown