Monday, February 21, 2011

Exporting and Uploading Mailbox Items using Exchange Web Services using the new ExportItems and UploadItems operations in Exchange 2010 SP1

Two new EWS Operations ExportItems and UploadItems where introduced in Exchange 2010 SP1 that allowed you to do a number of useful things that where previously not possible using Exchange Web Services. Any object that Exchange stores is basically a collection of properties for example a message object is a collection of Message properties, Recipient properties and Attachment properties with a few meta properties that describe the underlying storage thrown in. Normally when using EWS you can access these properties in a number of a ways eg one example is using the strongly type objects such as emailmessage that presents the underlying properties in an intuitive way that's easy to use. Another way is using Extended Properties to access the underlying properties directly. However previously in EWS there was no method to access every property of a message hence there is no way to export or import an item and maintain full fidelity of every property on that item (you could export the item as an EML but this doesn't provide any fidelity of the properties on item).

Now with these two new operations there is a method of exporting and uploading items and maintaining all the Mapi properties. The only real restriction is by default the maximum import payload is 25MB of base64 encoded data but these setting can be modified in the web.config file. The export/import format that these two operations use in a stream format which is a stream of all the Exchange properties separated with meta properties to represent the different property collections on the Item. This format while it bares some similarity to TNEF and Compound Message format (MSG) is not the same.

There are no methods in the EWS Managed API to use these operations so you need to use EWS Proxy code or just raw SOAP when writing applications or script to use this. However you do need the EWSid's of the Items and Folder to upload or export items and the Managed API is the easiest way of getting these. For this post I've create a sample of exporting the last received item in the Inbox first using the EWS Managed API to find the last item and then use raw SOAP to export the items.

I posted a downloadable copy of the following EWS Managed API script here the code itself looks like

$MailboxName = ""
$fileName = 'c:\exp.fts'
$cred = New-Object System.Net.NetworkCredential("","password")

$dllpath = "C:\Program Files\Microsoft\Exchange\Web Services\1.1\Microsoft.Exchange.WebServices.dll"
$service = New-Object Microsoft.Exchange.WebServices.Data.ExchangeService([Microsoft.Exchange.WebServices.Data.ExchangeVersion]::Exchange2010_SP1)
$service.TraceEnabled = $false

$windowsIdentity = [System.Security.Principal.WindowsIdentity]::GetCurrent()
$sidbind = "LDAP://<SID=" + $windowsIdentity.user.Value.ToString() + ">"
$aceuser = [ADSI]$sidbind
$service.Credentials = $cred

$folderid = new-object Microsoft.Exchange.WebServices.Data.FolderId([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox,$MailboxName)

$view = New-Object Microsoft.Exchange.WebServices.Data.ItemView(1)
$findResults = $service.FindItems($folderid,$view)
$itemid = $findResults.Items[0].Id.Uniqueid

$expRequest = @"
<?xml version="1.0" encoding="utf-8" ?>
<soap:Envelope xmlns:xsi=""
<t:RequestServerVersion Version="Exchange2010_SP1" />
<t:ItemId Id="$itemId"/>
$mbMailboxFolderURI = New-Object System.Uri($service.url)
$wrWebRequest = [System.Net.WebRequest]::Create($mbMailboxFolderURI)
$wrWebRequest.KeepAlive = $false;
$wrWebRequest.Headers.Set("Pragma", "no-cache");
$wrWebRequest.Headers.Set("Translate", "f");
$wrWebRequest.Headers.Set("Depth", "0");
$wrWebRequest.ContentType = "text/xml";
$wrWebRequest.ContentLength = $expRequest.Length;
$wrWebRequest.Timeout = 60000;
$wrWebRequest.Method = "POST";
$wrWebRequest.Credentials = $cred
$bqByteQuery = [System.Text.Encoding]::ASCII.GetBytes($expRequest);
$wrWebRequest.ContentLength = $bqByteQuery.Length;
$rsRequestStream = $wrWebRequest.GetRequestStream();
$rsRequestStream.Write($bqByteQuery, 0, $bqByteQuery.Length);
$wrWebResponse = $wrWebRequest.GetResponse();
$rsResponseStream = $wrWebResponse.GetResponseStream()
$sr = new-object System.IO.StreamReader($rsResponseStream);
$rdResponseDocument = New-Object System.Xml.XmlDocument
$Datanodes = @($rdResponseDocument.getElementsByTagName("m:Data"))
if ($Datanodes.length -ne 0){
$Data = [System.Convert]::FromBase64String($Datanodes[0].'#text')
$fsFileStream = new-object $fileName, ([io.filemode]::create), ([io.fileaccess]::write), ([io.fileshare]::none)
$fsFileStream.Write($Data, 0, $Data.Length);