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Set Mailbox Item Private Flag

On January 13, 2018

Thomas Stensitzki | MVP

0 Comment

EWS, Mailbox, Privacy

Exchange Server

1803 Views

Last updated: 2018-01-15

Problem

When you migrate messages from an alternative email solution (e.g. Lotus Notes) you might migrate sensitive content that must stay private in the new Exchange Server target location.

So how can you mark such messages as private?

Solution

The privacy level (Sensitivity) of a mailbox item is controlled by MAPI extended property 0x36.

0x36 = 0, sensitivity = normal
0x36 = 2, sensitivity = private

The command line tool searches for messages containing a given text as a subject substring.

The c# code sets the extended property 0x36 to 2.

A mailbox is accessed using Exchange Web Services. The EWS endpoint is discovered using AutoDiscover for the selected mailbox.

The item modification is handled by the following code segment:

foreach (var extendedProperty in Message.ExtendedProperties)
{
	if (extendedProperty.PropertyDefinition == extendedPropertyDefinition)
	{
		if (log.IsInfoEnabled)
		{
			log.Info(string.Format("Try to alter the message: {0}", Message.Subject));
		}
		else
		{
			Console.WriteLine("Try to alter the message: {0}", Message.Subject);
		}

		// Set the value of the extended property (0 is Sensitivity normal, 2 would be private)
		Message.ExtendedProperties[extendedPropertyindex].Value = 2;

		// Update the item on the server with the new client-side value of the target extended property
		Message.Update(ConflictResolutionMode.AlwaysOverwrite);
	}
	extendedPropertyindex++;
}

Usage

SetPrivateFlags.exe -mailbox user@domain.com -subject "[private]"

Search the mailbox for all messages having a subject string containing [private] and ask for changing each item if -logonly is not set to true.
If -logonly is set to true only a log will be created.

SetPrivateFlags.exe -mailbox user@domain.com -subject "[private]" -noconfirmation

Search the mailbox for all messages having a subject string containing [private] and change all found messages without confirmation.

Note

It should be noted that this solution is intended for use in migration scenarios.

When providing access to mailbox delegates you can enable access to your private elements as well. But access to shared mailboxes is not configured using the delegation workflow.

The code has been tested using Exchange Server 2013 CU15.

The program utilizes log4net to log detailed information to the file system. The configuration is controlled by the application's config file.