1/24/17 Update:  The script has been updated to v1.3, fixing support for mailboxes on Exchange 2010.  There are also some minor fixes, such as correctly using autodiscover when neither an EWS URL nor the Exchange Online switch is used.

4/18/16 Edit: I was reviewing this script for an unrelated reason when I discovered that I had used incorrect construction in the begin block since you cannot access parameter values in it.  I have updated the script in the download and the inline code at the end of the post that any any code that references parameters has been moved to the process block.

Exchange has the ability to send text messages to specific carriers in a few countries, and is enabled by default. This allows users to configure calendar notifications (such as changes to meetings that are occurring in the next three days) and rules to forward email as a text message. Users have to use OWA (or if you prefer the new name, Outlook on the web) to configure this. But what if your users do this before you realize it is enabled by default and now you want to disable it?

If you modify the role assignment policy to remove MyTextMessaging or modify OWA Mailbox policy to remove Text Messaging, it hides this feature from users, but it doesn’t disable anything already in place. You then decide to use PowerShell to run Clear-TextMessagingAccount for someone, but it says the user cannot be read. You can run it for your own account, but nobody else, even as an admin. This is because the write scope of the role that contains the cmdlet is Self. So how to remove the settings for another user?

I wrote a script that uses the EWS Managed API modify the hidden messages that contain the settings and delete any inbox rules that are forwarding to a mobile device. I should point out that doing it this way is unsupported, but I have used it successfully for mailboxes on Exchange 2013 and in Exchange Online.

The calendar notification settings and text messaging configuration are stored in folder associated items (FAI) in the root folder of the mailbox, in the roaming XML property of a user configuration message. Because of this, you can use the Microsoft.Exchange.WebServices.Data.UserConfiguration class to easily get messages with a specific subclass and retrieve this property without having to define a property set with the extended MAPI property. The subclass for the calendar notification settings is CalendarNotification.001 and text messaging configuration is TextMessaging.001. If you already have a service object created, you can get the message for calendar notification with these two lines:

The roaming properties of a user configuration message are stored in the Dictionary, XmlData, and BinaryData properties of the search result object. The property for the calendar notification settings (PR_ROAMING_XMLSTREAM as the XmlData property) is a binary value returned as a byte array, so it needs to be converted to a string cast as an XML object so it can be manipulated with XML methods:

The three notification types have their own node and contains an element whose value indicates whether it is enabled. Since I don’t care what the other options are, only that they are disabled, this can be done by directly setting the value for the element:

To write the data back to the XmlData property and save it in the mailbox, it needs to be converted back to a byte array. This isn’t done with a one-liner like converting from a byte array. The XML data is converted to a string, which is then converted to a byte array. There could be a more efficient way of doing this, but I don’t know it at the time of this writing. The first line is the one-liner to take the XML data and store it as a byte array in the property, the second saves the message back to the mailbox, and the two functions that convert XML to a string and a string to a byte array follow:

For the text messaging configuration, it is in the same property of its message. Once converted to XML, devices are stored in the MachineToPersonMessagingPolicies node, with a PossibleRecipient node for each device that has ever been configured. To simply delete any devices, you can remove all sub-nodes since there aren’t any others:

Then convert the XML data back to a byte array and save the message the same as before.

What remains are any inbox rules that may have been created that forward to a text messaging device. As an admin, you can use PowerShell to get rules, but you won’t see any rules that have been disabled in Outlook. Even if a rule is visible because it is enabled or has been disabled via OWA, and so you are able to see if a given rule is forwarding to a text messaging device, if you delete the rule, you will also delete any rules that are currently disabled via Outlook. What’s worse, you won’t even know if there are disabled rules that will be deleted because the warning is presented for every mailbox regardless of the existence of any applicable rules.

So the script will get all FAI messages that are rules and delete any that are forwarding to a device configured via the text messaging feature. The first step is to get the rules by searching for all FAIs in the inbox whose class is that of a rule:

After getting the rules, we need to retrieve the property that contains a rule’s actions, which is PR_EXTENDED_RULE_ACTIONS (0x0E990102) when on Exchange 2013+ or 0x65EF0102 when on Exchange 2010, a binary property:

Parsing the binary data is not easy (for me) because it includes pieces of variable-length information. If the entire value is converted to a string, however, an action that forwards to a configured text messaging device contains the string MOBILE: followed by the E.164-formatted phone number. So, all that needs to be done is to get the rule’s actions, convert it to string, check for MOBILE, and delete the rule:

The script supports on-premises and Exchange Online, autodiscover or specified URL, pipelining mailboxes into it, impersonation and specifying credentials. The output will contain what actions it took on a mailbox, including whether any of the features were not configured in the first place. You can run it multiple times against a mailbox without it having an issue that any or all features are not configured. The full script can be expanded below, and it can also be downloaded via the following link:

  Remove-TextMessagingConfiguration.zip (3.1 KiB)