Invite a non-Microsoft 365 attendee

1. In iCal/Calendar, double-click the event to which you want to invite people and the Info window will open (or from the menu bar select Edit -> Edit Event or Get Info).
2. Type your email address and/or name
3. Click Add Invitees and type the email address for the person you want to invite.
   
   
   

If you're inviting someone whose contact information is stored in Address Book

1. Start typing the person's name. iCal/Calendar provides a list of contacts.
2. Select the contact you want, and then press Return to select it.
3. Choose Window > Address Panel to open the Address panel.
   
   
   
4. Select one or more contacts in the Address panel, and then drag them over the open event editor.
5. To remove a person from the invitees list, click the arrow next to the email address and choose Remove Invitee, or select the email address and press the Delete key.
6. When you're ready to invite these guests to your event, click the Send button at the bottom of the event editor.