If people don’t receive invitations sent from Calendar on Mac
If you invited people to an event or to share a calendar but guests aren’t receiving your invitations, try these suggestions:
Make sure that your card in Contacts includes all your email addresses.
If the email address you used to send the invitation isn’t listed, Calendar might not recognise you as the person who created the event or calendar. See Edit contacts.
Make sure you’re using the correct email addresses by sending an email to each invitee. This also ensures that there’s nothing wrong with your account settings or internet access.
Make sure there’s nothing wrong with your internet connection or the internet connections of the people you’re trying to invite.
If you made changes to the event or shared calendar, refresh your calendars.
For shared calendars, make sure your account information is correct in Accounts preferences.