The Availability element is an optional child element of the Options element in ResolveRecipients command requests that indicates to the server that free/busy data is being requested by the client and identifies the start time and end time of the free/busy data to retrieve. The Availability element is an optional child element of the Recipient element in ResolveRecipient command responses that returns the status and free/busy data of the users or distribution lists identified in the request for the time identified by the StartTime and EndTime elements.

All elements referenced in this section are defined in the ResolveRecipients namespace.

Command request/response

Parent elements

Child elements

Data type

Number allowed

ResolveRecipients command request (section

Options (section

StartTime (section

EndTime (section

container ([MS-ASDTYPE] section 2.2)

0...1 (optional)

ResolveRecipients command response

Recipient (section

Status (section

MergedFreeBusy (section


0...1 (optional)

When the Availability element is included in a ResolveRecipients request, the server retrieves free/busy information for the users identified in the To elements included in the request, and returns the free/busy information in the MergedFreeBusy element in the response. If the Availability element is included in the ResolveRecipients request, the request MUST also include a valid StartTime element value. When the server parses the request, the server first resolves the recipients identified by the To elements, and then determines the users free/busy information for the specified time span, before returning the free/busy data in the MergedFreeBusy element.

Protocol Versions

The following table specifies the protocol versions that support this element. The client indicates the protocol version being used by setting either the MS-ASProtocolVersion header, as specified in [MS-ASHTTP] section, or the Protocol version field, as specified in [MS-ASHTTP] section, in the request.

Protocol version

Element support