This documentation is archived and is not being maintained.

Converting identifiers by using the EWS Managed API 2.0

EWS Managed API

Last modified: October 13, 2012

Applies to: EWS Managed API | Exchange Server 2007 Service Pack 1 (SP1) | Exchange Server 2010

Note: This content applies to the EWS Managed API 2.0 and earlier versions. For the latest information about the EWS Managed API, see Web services in Exchange.

You can use the Microsoft Exchange Web Services (EWS) Managed API to convert item identifiers that are used by Microsoft Exchange Server.

The following example shows how to convert an Outlook Web App identifier to an EWS identifier.

static void ConvertOwaIdtoEWSid(ExchangeService service, string idToConvert, string mailboxSMTP)
   // Specify the item or folder identifier, the identifier type, the SMTP address of the mailbox
   // that contains the identifier, and whether the item/folder identifier represents an archived
   // item or folder.
   AlternateId originalId = new AlternateId(IdFormat.OwaId, idToConvert, mailboxSMTP, false);

   // Send a request to convert the item identifier. This results in a call to EWS.
   AlternateId newId = service.ConvertId(originalId, IdFormat.EwsId) as AlternateId;

   Console.WriteLine("Converted identifier type: " + newId.Format);
   Console.WriteLine("Converted identifier: " + newId.UniqueId);

If you are converting public folder item or folder identifiers, use the AlternatePublicFolderId or AlternatePublicFolderItemId classes instead of the AlternateId class.

For information about compiling this code, see Getting started with the EWS Managed API 2.0.

  • Write appropriate error handling code for common search errors.

  • Review the client request XML that is sent to the Exchange server.

  • Review the server response XML that is sent from the Exchange server.

  • Set the service binding as shown in Setting the Exchange service URL by using the EWS Managed API 2.0. Do not hard code URLs because if mailboxes move, they might be serviced by a different Client Access server. If the client cannot connect to the service, retry setting the binding by using the AutodiscoverUrl(String) method.

  • Set the target Exchange Web Services schema version by setting the requestedServerVersion parameter of the ExchangeService constructor. For more information, see Versioning EWS requests by using the EWS Managed API 2.0.

  • Use HTTP with SSL for all communication between client and server.

  • Always validate the server certificate that is used for establishing the SSL connections. For more information, see Validating X509 certificates by using the EWS Managed API 2.0.

  • Do not include user names and passwords in trace files.

  • Verify that Autodiscover lookups that use HTTP GET to find an endpoint always prompt for user confirmation; otherwise, they should be blocked.