I can send emails but i cant receive any

I can send emails but i cant receive any

Hello,
After greatings, I'm using zoho (lite) and i created several email addresses through zoho, i can send emails from it but i cant receive anything
I have tried several times
But still it doesn't work properly
I sent an email from Careers@autismmena.org (my domain is autismmena.org) to more than 3 people's including my personal account
When ever i try (or the others) to send a reply it doesn't send it gives me a delivery failure in every time.
Can tou help me please