Zoho mail does not receive emails sent to domain account?

Zoho mail does not receive emails sent to domain account?

Hi, I set up a  new zoho account; with the plan to first test a=it and upgrade to a business account for me + one other person. Thing is, it is already going wrong at set up: account( sofie.pelsmakers@architectureforchange.com) works seemingly fine. Messages SENT from it, arrive speedily; but message sent to the account, never arrive!!! Why is this?

Sofie