Calendar Invites Not Being Received

Calendar Invites Not Being Received

Hello -- As a test, I scheduled a meeting in Zoho calendar and sent an invitation to my own non-Zoho email address. I've waited 45 minutes and never received the invitation (not even in the junk folder). However, within the event details, it shows a green thumbs up that the event will be attended by both me (as the organizer) and by the invitee (i.e., my non-Zoho email). Since I never received the invitation, I have zero confidence that any of my clients would receive an invite either. Can someone please advise on how to fix this? Or does the Calendar simply not work? Thanks.