Insert available meeting times in Outlook through 'Outlook Integration with Inbox'

1. Open Outlook
2. Create a new message. Be sure to do this before continuing to step 3. The 'Outlook Integration with Inbox' options change depending on whether you have a new message open.
3. Click the Salesforce icon in the top toolbar.
4. In the side panel, click the Compose tab, and select Availability. 
5. On the screen that appears, click one or more available time slots. Click the arrows in the upper-right corner to move among different weeks, or click Today to return to the current week.
6. (Optional) If you have access to a someone else's calendar—for example, because you're on a shared company calendar or the person explicitly shared his or her calendar with you—those shared calendars appear also. Shared calendars appear under Attendees on the left side of the screen and are displayed in different colors in the calendar on the right.

• Click a time on a shared calendar to insert that person's availability in the email.
• To show or hide a person's shared calendar, check or uncheck the box to the left of the person's name or email address.
• To remove that person from the list of shared calendars, click X to the right of the person's name or email address.

7. (Optional) If you have write access to a person's shared calendar, you can send the invitation on behalf of that person by selecting their name from the Choose Meeting Owner list in the upper-left. To appear in the list, the person must use Inbox and be a part of the same Salesforce organization. The email will appear to come from this person to the message recipients.
8. (Optional) Do any of the following:

• In the fields on the left, enter a title, select a duration, and enter a location and description for the event.
• The person to whom you addressed the email message is selected as an attendee by default. Click Add an attendee to invite others.

9. Click Insert Availability. The message screen appears with the available times listed.

Note the following:

• After the recipient accepts an available time slot, you receive a calendar invite that holds a space in your calendar automatically.
• If you send an email containing available times to multiple recipients, the first person to select the time RSVPs that time for all the others.
• Insert Availability makes scheduling a meeting in a different time zone a seamless experience for you and the recipient. To change the time zone, click the drop-down menu above the calendar.
• If you get booked for a time and you have sent this time to another recipient, the Insert Availability feature removes that time from your invitation automatically, as it is no longer available.
• For more information, review Use Insert Availability to Optimize Scheduling Meetings.