Accept or decline calendar event invitations in Microsoft Entourage
- Open the event invitation message in your Inbox. The message should appear in a new window or the Preview pane of the Entourage main window.

- Click on one of the links to either accept, decline, or tenatively accept the invitiation. A dialog box appears so that you can send a response to the invitation, if one was requested. (For new event invitations, responses are requested by default.)
- Accept means that you plan to attend the event, and you have added it to your calendar accordingly
- Decline signifies that you do not intend to go to the appointment, and therefore it is not added to your calendar
- Tentatively Accept indicates that you are unsure about the event, and may yet accept or decline it — but in the mean time, it will be listed on your calendar even though it will not block your schedule's free/busy status. (Entourage can also be set to automatically accept new invitations tenatively when they reach your Inbox.)
- Choose whether you want to respond to the person who invited you or not and then click "OK." If you choose to respond, you can send your comments (choose "Yes, with comments") or just a notice that you have accepted or declined the invitation (choose "Yes, without comments"). You may also choose to not respond; choose "No."

That's it! Once you have accepted the event (even tentatively), it is added to your calendar. If you declined the event, it is not added to your calendar.
If the person who invited you makes changes to the meeting, you should get another message that updates the event. You have to accept the updates before the changes are made in your calendar.