Exchange ItemID differs from GlobalAppointmentID for Outlook AddIn

Question

The problem I'm having is that the GlobalAppointmentID of a Outlook Appointement created using a Outlook FormRegion differs from that of the ItemID when using EWS Managed API.

I'm creating an Outlook addIn that allows users to add customer and project information to a meeting. The addIn also stores the appointment ID and meeting data in a database and a service will periodically check the ID to update the appointment data.

Ok so here is how I use the AddIn:

Outlook.AppointmentItem appointement = (Outlook.AppointmentItem)this.OutlookItem;

appointement.Save();

string ExchangeID = appointement.GlobalAppointmentID;

Here the GlobalAppointmentID is: 040000008200E00074C5B7101A82E0080000000060CADC517255CE01000000000000000010000000847A9CD89052DC49BA28DC8AAFBBB4BA

But the EWS managed API expects something like: AAMkADViNTJlZTg5LTIwYWMtNGY3My1hOWZiLTZiOTM3OTk3Nzk1YQBGAAAAAAAEfbmEhAMsRZur9AvsphPMBwCysaa5HwPMRanSoWSnKrckAAAAXAL/AACysaa5HwPMRanSoWSnKrckAAAAXCxwAAA=

to Bind a AppointmentItem from the service. There is an option to solve this but only using auto-generated proxies and not the Managed API link to proxy solution

So is there a way to either from the EWS Managed API search for GlobalAppointementID or from an Outlook AddIn retrieve the ItemID?

score 3 · Accepted Answer · answered May 22 '13 at 07:02

The IDs can be represented different ways. Outlook uses the first form, EWS the second.

To convert, use the ConvertID method.

Here are example request/response calls in raw SOAP format (with these examples, you should be able to implement them with the API):
Outlook HexEntryID to Exchange EWSID

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:typ="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:mes="http://schemas.microsoft.com/exchange/services/2006/messages">
   <soapenv:Header>
      <typ:RequestServerVersion Version="Exchange2007_SP1"/>
      <typ:MailboxCulture>en-US</typ:MailboxCulture>
   </soapenv:Header>
   <soapenv:Body>
      <mes:ConvertId DestinationFormat="EwsId">
         <mes:SourceIds>
            <typ:AlternateId Format="HexEntryId" Id="0000000068C940C[snip]63136C3D0000" Mailbox="user@domain.com"/>
         </mes:SourceIds>
      </mes:ConvertId>
   </soapenv:Body>
</soapenv:Envelope>

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ServerVersionInfo MajorVersion="14" MinorVersion="0" MajorBuildNumber="722" MinorBuildNumber="0" Version="Exchange2010" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
   </s:Header>
   <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <m:ConvertIdResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
         <m:ResponseMessages>
            <m:ConvertIdResponseMessage ResponseClass="Success">
               <m:ResponseCode>NoError</m:ResponseCode>
               <m:AlternateId xsi:type="t:AlternateIdType" Format="EwsId" Id="AQMkADkyZTQxNjUzL[snip]YxNsPQAAAA==" Mailbox="user@domain.com"/>
            </m:ConvertIdResponseMessage>
         </m:ResponseMessages>
      </m:ConvertIdResponse>
   </s:Body>
</s:Envelope>

Exchange EWSID to Outlook HexEntryID:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:typ="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:mes="http://schemas.microsoft.com/exchange/services/2006/messages">
   <soapenv:Header>
      <typ:RequestServerVersion Version="Exchange2007_SP1"/>
   </soapenv:Header>
   <soapenv:Body>
      <mes:ConvertId DestinationFormat="HexEntryId">
         <mes:SourceIds>
            <typ:AlternateId Format="EwsId" Id="AQMkADkyZTQxNjUzLTcwZTQtNGRlNS04M2VmLWMxYmIBNWJi[snip]YxNsPQAAAA==" Mailbox="user@domain.com"/>
         </mes:SourceIds>
      </mes:ConvertId>
   </soapenv:Body>
</soapenv:Envelope>

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ServerVersionInfo MajorVersion="14" MinorVersion="0" MajorBuildNumber="722" MinorBuildNumber="0" Version="Exchange2010" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
   </s:Header>
   <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <m:ConvertIdResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
         <m:ResponseMessages>
            <m:ConvertIdResponseMessage ResponseClass="Success">
               <m:ResponseCode>NoError</m:ResponseCode>
               <m:AlternateId xsi:type="t:AlternateIdType" Format="HexEntryId" Id="0000000068C940[snip]136C3D0000" Mailbox="user@domain.com"/>
            </m:ConvertIdResponseMessage>
         </m:ResponseMessages>
      </m:ConvertIdResponse>
   </s:Body>
</s:Envelope>

Note that there is a difference in using these two types of ID's when using recurring appointments and occurrences:
Where EWS IDs differ for every single occurrence, the Outlook hex entry ID are identical for all:

FindItem response for a recurring event with one exception - note the different ItemIDs:

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ServerVersionInfo MajorVersion="14" MinorVersion="0" MajorBuildNumber="722" MinorBuildNumber="0" Version="Exchange2010" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
   </s:Header>
   <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <m:FindItemResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
         <m:ResponseMessages>
            <m:FindItemResponseMessage ResponseClass="Success">
               <m:ResponseCode>NoError</m:ResponseCode>
               <m:RootFolder TotalItemsInView="10" IncludesLastItemInRange="true">
                  <t:Items>
                     <t:CalendarItem>
                        <t:ItemId Id="AAMkADkyZTQxNjUzLTcwZTQtNGRlNS04M2VmLWMxYmJiNWJiNTBlNgFRAAgI0B8WRv2AAEYAAAAAgq3iY5OVdkmtnHS/lxCbwgcAhKYXWHH/akCFAFNVQGZiCgAAAAAAIQAAhKYXWHH/akCFAFNVQGZiCgACKa9YrQAAEA==" ChangeKey="DwAAABYAAACEphdYcf9qQIUAU1VAZmIKAAIpr2i3"/>
                        <t:ItemClass>IPM.Appointment.Occurrence</t:ItemClass>
                        <t:Subject>Recurring appointment with one exception</t:Subject>
                        <t:Sensitivity>Normal</t:Sensitivity>
                        <t:DateTimeCreated>2013-05-22T06:51:26Z</t:DateTimeCreated>
                        <t:LastModifiedTime>2013-05-22T06:52:20Z</t:LastModifiedTime>
                        <t:Start>2013-05-15T10:30:00Z</t:Start>
                        <t:End>2013-05-15T11:00:00Z</t:End>
                        <t:IsRecurring>true</t:IsRecurring>
                        <t:CalendarItemType>Occurrence</t:CalendarItemType>
                     </t:CalendarItem>
                     <t:CalendarItem>
                        <t:ItemId Id="AAMkADkyZTQxNjUzLTcwZTQtNGRlNS04M2VmLWMxYmJiNWJiNTBlNgFRAAgI0B/fcWdAAEYAAAAAgq3iY5OVdkmtnHS/lxCbwgcAhKYXWHH/akCFAFNVQGZiCgAAAAAAIQAAhKYXWHH/akCFAFNVQGZiCgACKa9YrQAAEA==" ChangeKey="DwAAABYAAACEphdYcf9qQIUAU1VAZmIKAAIpr2i3"/>
                        <t:ItemClass>IPM.OLE.CLASS.{00061055-0000-0000-C000-000000000046}</t:ItemClass>
                        <t:Subject>The exception</t:Subject>
                        <t:Sensitivity>Normal</t:Sensitivity>
                        <t:DateTimeCreated>2013-05-22T06:51:58Z</t:DateTimeCreated>
                        <t:LastModifiedTime>2013-05-22T06:52:20Z</t:LastModifiedTime>
                        <t:Start>2013-05-16T12:00:00Z</t:Start>
                        <t:End>2013-05-16T12:30:00Z</t:End>
                        <t:IsRecurring>true</t:IsRecurring>
                        <t:CalendarItemType>Exception</t:CalendarItemType>
                     </t:CalendarItem>
                     [snip]
                     Other occurrences removed
                     [snip]
                  </t:Items>
               </m:RootFolder>
            </m:FindItemResponseMessage>
         </m:ResponseMessages>
      </m:FindItemResponse>
   </s:Body>
</s:Envelope>

Conversion for EWSID to HexEntryID for both these ItemIDs results in

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ServerVersionInfo MajorVersion="14" MinorVersion="0" MajorBuildNumber="722" MinorBuildNumber="0" Version="Exchange2010" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
   </s:Header>
   <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <m:ConvertIdResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
         <m:ResponseMessages>
            <m:ConvertIdResponseMessage ResponseClass="Success">
               <m:ResponseCode>NoError</m:ResponseCode>
               <m:AlternateId xsi:type="t:AlternateIdType" Format="HexEntryId" Id="0000000082ADE26393957649AD9C74BF97109BC2070084A6175871FF6A40850053554066620A000000000021000084A6175871FF6A40850053554066620A000229AF58AD0000" Mailbox="user@domain.com"/>
            </m:ConvertIdResponseMessage>
         </m:ResponseMessages>
      </m:ConvertIdResponse>
   </s:Body>
</s:Envelope>

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ServerVersionInfo MajorVersion="14" MinorVersion="0" MajorBuildNumber="722" MinorBuildNumber="0" Version="Exchange2010" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>
   </s:Header>
   <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <m:ConvertIdResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
         <m:ResponseMessages>
            <m:ConvertIdResponseMessage ResponseClass="Success">
               <m:ResponseCode>NoError</m:ResponseCode>
               <m:AlternateId xsi:type="t:AlternateIdType" Format="HexEntryId" Id="0000000082ADE26393957649AD9C74BF97109BC2070084A6175871FF6A40850053554066620A000000000021000084A6175871FF6A40850053554066620A000229AF58AD0000" Mailbox="user@domain.com"/>
            </m:ConvertIdResponseMessage>
         </m:ResponseMessages>
      </m:ConvertIdResponse>
   </s:Body>
</s:Envelope>

Well that worked! or at least a version of it here is how you use the convert function with EWS Mangaed API [link](http://blogs.msdn.com/b/brijs/archive/2010/09/09/how-to-convert-exchange-item-s-entryid-to-ews-unique-itemid-via-ews-managed-api-convertid-call.aspx) — Christopher Overall, May 22 '13 at 08:10
Just a clarification, you use the EntryID of the Appointment object from Outlook converted to hex using something like: `private static string GetObjectIdStringFromUid(string id) { var buffer = new byte[id.Length / 2]; for (int i = 0; i < id.Length / 2; i++) { var hexValue = byte.Parse(id.Substring(i * 2, 2), NumberStyles.AllowHexSpecifier); buffer[i] = hexValue; } return Convert.ToBase64String(buffer); }` — Christopher Overall, May 22 '13 at 08:34
Is Outlook hex entry ID the same for the same appointment across organizer and attendees? — João Pimentel Ferreira, Mar 19 '22 at 11:53

score 0 · Answer 2 · answered May 21 '13 at 16:23

0

Outlook appointment id wraps external (iCal) appointment ids. You need to parse it: http://msdn.microsoft.com/en-us/library/ee157690(v=exchg.80).aspx

answered May 21 '13 at 16:23

Dmitry Streblechenko

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I'm not sure I'm following you. Are you saying that the GlobalAppointementID is wrapping the Exchange ItemID? I don't think that is the case since the ItemID is longer than the GlobalAppointementID. – Christopher Overall May 22 '13 at 07:19
I am talking about an appointment id that is set when, for example, an incoming meeting request in the iCal format is converted to an Outlook appointment. The original appointment id will be wrapped inside the GlobalAppointementID property. If you are talking about an entry id, then the answer given by Jan should work for you. – Dmitry Streblechenko May 22 '13 at 16:30

Exchange ItemID differs from GlobalAppointmentID for Outlook AddIn

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