Open Outlook
Go to Calendar
Select New Meeting or New Appointment
Enter the meeting title
Add required attendees
Set the date and time
Add the location if needed
Add a message or agenda
Set recurrence if needed
Choose a reminder time
Click Send
For an existing meeting, open the event and click Send Update
To share availability only, create a meeting request with your preferred times
To send a calendar invite from email, use Insert > Outlook Item if available
To forward a calendar request, open the event and click Forward
To send from Outlook mobile, open Calendar, create an event, add attendees, and tap Send