Exchange 2007 Search - Part 3: The Search Process

  • Articolo

This blog is the third of three which focus on Exchange 2007 Search and Content Indexing. The titles of the three blogs are as follows:

Exchange 2007 Search - Part 1: Introduction to Exchange 2007 Search
Exchange 2007 Search - Part 2: Content Indexing
Exchange 2007 Search - Part 3: The Search Process (this Blog)

Search Methods for Exchange 2007

There are five basic ways to search mailbox data.

Three types of search Methods can be using when querying data directly against an Exchange 2007 Sever:

1. Exchange Search (New Content Indexing Feature) is used when a search request for Mailbox store data is requested. Outlook is in online mode and indexing is enabled on the store.

2. Store Search is the default search method that is used if Content Indexing is disabled on the Exchange Server. This is also the method used in previous versions of Exchange. Outlook is in online mode and indexing is disabled.

This blog post focuses on the first option - Exchange Search with Outlook 2007 in online mode and Exchange 2007 indexing is enabled. The difference between searching the Index with and without WDS installed on the Outlook 2007 client machine is covered in detail later in this section.

3. Outlook Online Search w. WDS - Outlook is online mode with WDS enabled to index the store.

This method is disabled in WDS by default beginning with WDS version 3.01 and not recommended because it causes performance issues on the Exchange 2007 server. It can be enabled or disabled on (a) an individual client machine or (b) by group policy. The Administration Guide for 3.01 and the Group Policy for Windows Search provide detailed information, while the 4.0 Administrator’s Guide provides general information:

Windows Desktop Search 3.01 Administration Guide
https://www.microsoft.com/downloads/details.aspx?FamilyID=00645e54-70a8-4d05-906d-af8773cbc728&DisplayLang=en

Group Policy for Windows Search
https://technet.microsoft.com/en-us/library/cc732491.aspx

Note: The latest version of WDS is 4.0

Windows Search 4.0 Administrator's Guide
https://technet.microsoft.com/en-us/library/cc772446.aspx

For further information on why this method is disabled by default beginning with WDS 3.01 and the performance problems it causes if enabled, please see this reference:

905184  Exchange 2000 Server and Exchange Server 2003 performance may be affected when desktop search engine software is running on Outlook or other MAPI client computers
https://support.microsoft.com/default.aspx?scid=kb;EN-US;905184

Two additional methods of search are available with Outlook 2007:

4. Outlook Cached Search - Outlook is in cached mode and Windows Desktop Search is not installed.

5. Outlook Cached Search w. WDS - Outlook in cached mode and Windows Desktop Search is installed, the local index files are used.

The Instant Search feature, new to Outlook 2007 and which is only available if Windows Desktop Search is installed on the client machine, gives the user the following functionality:

Hit Highlighting, which helps the user understand why an item was returned with their search results by highlighting the matching text.

Word Wheeling, automatically filters the items in the current view based on what the user types in, and continues to update as the search is modified, this is sometimes referred to as “Search as I type”.

Query Builder, allows the user to use query syntax, explained in further detail later in this section.

All Folder Search, also examined in further detail later in this chapter this feature allows an Outlook user to search multiple folders in their Outlook profile, including multiple top-level folders.

Note: If you are accessing an Exchange 2007 Server with Outlook 2007 (but without installing WDS), hit highlighting will still function.

Searching Mailbox Data – More Information

Locale and Language
In order to return consistent search results in environments of multiple locales, the following points must be true:

  • The locale of the message must match the language the email was written
  • Search queries are submitted in a single language
  • The language of the search query must match the locale of the client computer as identified by the connection to the server

Searching Junk and Dumpster Items
All your mailbox folders are available for search in Outlook 2007 and OWA 2007, including the junk mail folder.  It is not currently possible to search your mailbox dumpster from Outlook or OWA.  For a dumpster workaround, see the section below on Cross Mailbox Search.

Cross Mailbox Search
An Exchange Administrator has the ability using the Exchange Management Shell to search across multiple mailboxes using the Export-Mailbox cmdlet. This cmdlet will search all mailbox items in multiple, or a single mailbox. What is interesting about this cmdlet is that a search of a single mailbox or across mailboxes will include the dumpster of a mailbox or multiple mailboxes. Deleted items are converted to regular messages and included in the search. Items that match your search are then exported to a specified pst or specified single target mailbox. You can use Cross Mailbox Search to search for text in the Subject or Body of the message. For additional information on how to perform a Cross Mailbox search, see the links below:

How To Use Exchange Search to Locate Messages for the Purposes of Review or Deletion
https://technet.microsoft.com/en-us/library/aa997688.aspx

Exchange Server 2007 Cross Mailbox Search using Export-mailbox
https://msexchangeteam.com/archive/2006/12/18/431934.aspx

Searching Attachments
With the use of installed IFilters Exchange Search indexes attachments. Depending on the client you are using to search, you may need to take additional steps to include attachments in the search.

  • For OWA 2007, attachments in your search are included automatically
  • For Outlook 2007, use Instant Search or Advanced Find
  • For Outlook 2003, use Find or Advanced Find and select Subject Field & Message Body
  • For Outlook 2002, use Advanced Find and select Subject Field & Message Body

Note that indexing is currently performed on embedded items for one level. If you have an email within an email, Exchange 2007 Search will index both items. If there is another email embedded in the second email, that email will not be indexed.

Another issue is that if you combine attachment keyword searching with another form of searching such as a keyword in an attachment (which gives hits) and a keyword in the TO: field (which gives hits), you will not get any hits if you combine these two parameters into one search because the attachment keywords and the TO: keywords are kept in different store tables. The only workaround currently is to do the searches separately and then compare the results for matching items.

When a user is in online mode in Outlook 2003 or Outlook 2007 and creates a search request within Outlook, the request is sent to the Exchange 2007 Server and serviced by one of two methods, Exchange Search or Exchange Store Search.  A table comparing the two methods is below, followed by an overview of the process of querying using Exchange Search.

Exchange Search

Exchange Store Search

Faster

Slower

Searches the Index

Searches the Store

Uses words, phrases, sentences

Matches streams of bytes

Ignores punctuation, spaces, not case sensitive

Exact match of characters, case sensitive

Does not support substring matching

Supports substring matching

Searches attachments (based on available filters) (Online mode and OWA only)

Does not search within attachments

Text Searches only

Full set of MAPI restrictions (such as Date & Time)

Uses the Catalog built by MSSearch

Searches messages based on search parameters

Can search in various languages

Not language-aware

The query processor checks on the status of the msftesql-Exchange and MSExchangeSearch services every 30 seconds and caches their status in Memory; if either is unavailable Exchange Store Search is used.

Note that if the catalog is unavailable, or the database is not enabled for full text search, then Exchange Store Search is used.

Note that Substring searching refers specifically to a substring anywhere within a word rather than simply Prefix searching which refers to a substring at the beginning of a word.

Exchange Search Process without WDS Installed

The following Exchange Search procedure assumes the Outlook online mode client is using the Advanced Find feature, or does not have Windows Desktop Search (WDS)/Instant Search, or any other local indexing application installed.

1. A client (Outlook or Web Client) creates search query, a search query contains the restriction and the scope, the “What” and “Where”. 

a. The Exchange Server Query Processor inside the store takes the query and builds a request based on the restriction and scope. The restriction is evaluated and converted to a MAPI restriction tree, providing the parameters of the query. The scope is the folder list and sets the boundaries of the query.

During this query evaluation (if a Noise Word File has been implemented), the query processes common words called Noise words are removed. “A”, “and”, “the”, are all examples of noise words.

b. The query is now sent to MSSearch.

2. MSSearch creates a temporary folder called a Search Folder that will contain its results. MSSearch then reads the Index Catalogs and returns the Document ID’s from the catalog that match the request.

a. The Search Folder is stored in a hidden folder hierarchy with a top level folder named Restrictions. These search folders are only temporary and the client does not directly access them.

3. The Query Processor then reads the Property Store to find the Entry ID’s that match the Document ID’s returned by MSSearch, these back links are then stored in the Search Folder.

4. A restricted view is then created based on the contents of the search folder. The information store then sends this view to the client. The client can now see all the items that match the restriction and scope of their query.

a. The search folder is deleted by the store when not used for a certain amount of time.

 

Exchange Search Process with WDS Installed

In order to perform Advanced Searching in online mode (against the Index, not against the Store), Windows Desktop Search (WDS) must be installed. That can be illustrated by using an advanced search example of Phrase Searching.

In our example (Outlook 2007 SP1 in online mode) phrase searching using Instant Search fails against Exchange 2007 SP1 with indexing enabled against mailboxes if WDS is not installed. Phrase searches use quotation marks. For example, if you do a phrase search using Instant Search for “One Two Three” you receive the same results if you search for One Two Three (without “”).  The result you receive is that One and Two and Three all exist in the email, whether they are in the subject or the title of the email - all three terms have to be there to get hits, but One Two Three does not have to be in exact order.

By design in Exchange 2007 with Indexing enabled, Phrase Searching (i.e., using quotation marks to search for a phrase in the subject or body of a message) using Instant Search in Outlook 2007 online mode only works if Windows Desktop Search (WDS) is installed. This is by design in Outlook 2007 because the Semantic Analyzer Component of Windows Desktop Search (WDS) is required by Instant Search for advanced searching syntax (also called advanced search grammar or advanced searching language). This type of searching is officially known as Advanced Query Search or AQS that is only added to Instant Search from WDS.

Phrase and Keyword Searching
If you want to do phrase searching (using “”) with Outlook 2007 Instant search in online mode with Exchange 2007, you must install Windows Desktop Search to go along with Outlook 2007. In summary, this is by design in Exchange 2007 and by design in Outlook 2007. This applies to all types of advanced queries against the Exchange 2007 index - WDS must be installed on the Outlook 2007 client in online mode.
When you install Outlook 2007, Outlook 2007 shows a prompt to have WDS installed
because Outlook 2007 would like to make use of the semantic analyzer component in WDS. Once WDS is installed, WDS enables Instant Search to perform AQS queries such as phrase searching (using “”), keyword searching and more. Online mode search works without WDS, but the AQS or Advanced Query Syntax such as using quotes for searching does not work. AQS is the query language for WDS and can be used to narrow the scope of your searches. For example, using AQS you can use keywords like sent: <date>, from: <person>, read: yes/no, NOT, AND, +, OR, to name a few. For a complete list of AQS search options, click on the following links:

Chapter 11: Searching Outlook Data
https://msdn.microsoft.com/en-us/library/cc513841.aspx

Advanced Query Syntax
https://msdn.microsoft.com/en-us/library/Bb266512(VS.85).aspx

Advanced Query Syntax
https://msdn.microsoft.com/en-us/library/aa965711.aspx

Advanced Query Syntax: What, Where, Why, and How
https://blogs.msdn.com/cheller/archive/2006/12/05/advanced-query-syntax-what-where-why-and-how.aspx

NOTE: Outlook 2007 without WDS installed will not support the Advanced Query Syntax. This functionality is only provided with Windows Desktop Search.

Outlook 2007 with WDS installed supports Prefix and Exact Phrase Matching when double quotes are used around any word or words to specify an Exact Phase. 

Windows XP does not have Windows Desktop Search (WDS) installed by default. If you want to use the Advanced Query Search functions in Instant Search in Outlook 2007 online mode such as searching for phrases by using quotation marks, you will need to include Windows Desktop Search as a part of the Outlook 2007 install or add WDS after installing Outlook 2007.

WDS is installed by default on Windows Vista and Windows 7.  Therefore, Outlook 2007 installed on Windows Vista and Windows 7, in online mode, is able to utilize the Advanced Query Search functions by default.

OWA uses Basic Search instead of Advanced Search Query. Therefore, when using OWA to search the Exchange 2007 index on the server, it is by design that phrase searching and other advanced queries do not work. 

Prefix matching is the default for the Advanced Find feature in earlier versions of Outlook but this is not necessarily the case in Outlook 2007 and later versions. The table below lists the different modes and searching features in Outlook 2007 and whether or not Prefix searching is supported. Note that the table below refers to Prefix matching specifically (the beginning of a word), rather than Substring searching (a string found anywhere in word):

Mode WDS Installed   WDS Not Installed  
  Advanced Find Simple Find Advanced Find Simple Find
Cached Mode No No Yes Yes
Online  Mode Yes Yes Yes Yes

Support Matrix for Prefix Matching

Note also that when Indexing is enabled and available and the mailbox has been crawled, Advanced Find in Online Mode uses Exchange Search when it searches for a property in a message that is indexed by Content Indexing, uses Store Search when it searches for a property in a message that is not indexed by Content Indexing, and uses a combination of Exchange Search and Store Search for a complex search of a combination of properties in a message, one of which is indexed by Content Indexing and one of which is not indexed by Content Indexing.

Further Information on WDS and Outlook

Outlook 2007 is the first client version providing Instant Search in a pane which integrates Windows Desktop Search (WDS) into the Outlook interface. Instant Search makes it possible to easily search all mail folders in online mode and all personal folder files at the same time. Instant Search works in online mode against Exchange 2007 mailboxes. Instant Search also works in online mode against Exchange 2003 and Exchange 2000 mailboxes. For further information and to download WDS, see the following link:

Windows Desktop Search 4.0
https://www.microsoft.com/windows/products/winfamily/desktopsearch/choose/windowssearch4.mspx

Outlook 2007 with WDS installed allows you to return results for the selected folder (only) or All Folders. There is not an option for subfolder searching. However, this can always be performed through the Advanced Find feature.

Note that in previous versions of Outlook, WDS is not integrated into the Outlook interface. In Outlook 2003 and Outlook 2002, the Advanced Find dialog only allows you to search one mailbox folder plus its subfolders. You can choose to search the Mailbox top level folder and its subfolders and you can then search all items in the Mailbox in online mode. Or you can search one personal folder plus its subfolders at a time. However, you cannot search multiple top level folders or multiple .pst files (or a combination of folders and .pst files) at the same time. In Outlook 2003 and Outlook 2002, you must use the WDS interface by itself to be able to search all items in the mailbox and all items in personal folders at the same time.

Searching Exchange 2007 Public Folder Databases with Outlook 2007

Using Instant Search in Outlook 2007 or Advanced Find in Outlook 2007 or Outlook 2003, For Exchange 2007, you can search Public folders only in cached mode and only your Public Folder Favorites and only when you check the Cached Exchange Mode Settings box which says Download Public Folder Favorites. You can also optionally mandate local cached indexing of public folder data on a per machine basis or by group policy. 

 

Indexing Exchange 2007 Public Folder Databases

Note that Exchange 2007 indexes only mailbox store databases. In Exchange 2000 and Exchange 2003, full-text indexing could also be implemented for the public store database. That functionality has been replaced with SharePoint 2007 SP1 server running on Windows 2003 to index Exchange Server 2007 SP1 public folders for Exchange 2007 SP1. For further information, see the following links:

942390 Description of the SharePoint Server 2007 issues that are fixed by the 2007 Microsoft Office servers Service Pack 1
https://support.microsoft.com/default.aspx?scid=kb;EN-US;942390

If the SharePoint 2007 server is on Windows 2008 64-bit, there is an issue that is fixed in SharePoint 2007 SP2 which will allow SharePoint 2007 on Windows 2008 to be able to index Exchange 2007 SP1 public folders. Note that it is required that you apply BOTH Windows SharePoint Services 3.0 Service Pack 2 and Microsoft Office SharePoint Server 2007 Service Pack 2 (64-bit versions):

KB Article Links

953338 Description of Windows SharePoint Services 3.0 SP2 and of Windows SharePoint Services 3.0 Language Pack SP2
https://support.microsoft.com/default.aspx?scid=kb;EN-US;953338

953334 Description of 2007 Microsoft Office servers Service Pack 2 and of 2007 Microsoft Office servers Language Pack Service Pack 2
https://support.microsoft.com/default.aspx?scid=kb;EN-US;953334

Download Links

Service Pack 2 for Windows SharePoint Services 3.0, x86 & x64
https://www.microsoft.com/downloads/details.aspx?FamilyId=79BADA82-C13F-44C1-BDC1-D0447337051B&displaylang=en

Service Pack 2 for Office SharePoint Server 2007, x86 & x64
https://www.microsoft.com/downloads/details.aspx?FamilyId=B7816D90-5FC6-4347-89B0-A80DEB27A082&displaylang=en

 

Summary

In summary, there are five basic ways to search Exchange 2007 mailbox data. This blog post focused on the first option - Exchange Search with Outlook 2007 in online mode with Exchange 2007 indexing enabled. Searching the Index with WDS installed on the Outlook 2007 client machine provides a new feature called Instant Search and includes the ability to do Advanced Query Searching. Also, using Instant Search that has WDS integrated into the Outlook 2007 interface allows you to search all mailbox folders in online mode and all .pst files simultaneously in a supported and reliable manner.  For performance reasons, indexing the mailbox store by WDS is disabled by default.

Search queries are performed in one language only, the language of the client performing the search. Cross Mailbox Search to a target mailbox or target .pst file is available through the Export-Mailbox command. Attachment searching, new to Exchange 2007, is only provided with the use of installed default Filters and additional Filters may be installed for other document types. In order to do attachment searching, you must be in online mode or use OWA. Instant Search automatically includes attachments and Advanced Find can search attachments in Outlook 2007, Outlook 2003, and Outlook 2002. OWA 2007 includes attachment searching automatically.

Exchange Search (default) is preferred over Store Search (only used when the Index Catalog is not present or not available). Exchange Search is much faster than Store Search, searches words and phrases instead of streams of bytes, searches attachments, and can search in various languages.

Searching Exchange 2007 Public Folder Databases with Outlook 2007 (and Outlook 2003) is only possible if you are in Cached Exchange Mode, and only on Public Folder Favorites, and only if you check the box which says Download Public Folder Favorites.

By design, Exchange 2007 only indexes mailbox store databases, while both previous versions Exchange 2003 and 2000 also indexed public folder databases. By design, the current method of indexing Exchange 2007 public folder databases is to use SharePoint 2007.

In Exchange 2007 SP1, SharePoint 2007 SP1 is used to index public folder databases. SharePoint 2007 SP1 servers can currently index public folder databases on Exchange 2007 SP1 servers. SharePoint 2007 SP2 servers running on Windows 2008 are expected to be able to index Exchange 2007 SP1 public folder databases.

 

Conclusions

Exchange 2007 full-text indexing is now a best practice for all Exchange 2007 mailbox databases due to the fact that searching is much faster, mail is immediately indexed when it arrives, the reduced catalog size, and both Search and Index are much less resource intensive than previous versions.

Crawling in Exchange 2007 is now performed automatically as new items arrive or a significant event such as a mailbox move to a database occurs rather than on a schedule as in previous versions. This means that the Catalog Index is always up-to-date within seconds of new items arrival. Exchange 2007 provides a Noise Word file capability per the language of the client.

Exchange 2007 Content Indexing for High Availability SCC servers is much like Clustered Servers content indexing for Exchange 2003 and Exchange 2000: there is one copy of the Catalog. For Exchange 2007 

CCR servers, there are two copies of the mailbox database and each database has its own unique catalog which is only crawled at any one time on the active node.

There are five basic ways to search Exchange 2007 mailboxes, and this bulletin concentrates specifically on the new Features available for Outlook 2007 online mode clients with WDS installed against Exchange 2007 mailbox database with indexing enabled such as searching attachments and using Advanced Query Syntax. Indexing of Exchange 2007 public folder databases has been completely deprecated for Exchange 2007 and searching for Exchange 2007 public folder databases has been partially deprecated in Outlook 2007. The current method of indexing and searching for Exchange 2007 public folder databases is now using SharePoint 2007.

In conclusion, deploying Exchange 2007 together with Outlook 2007 and SharePoint 2007 gives advanced features, much faster and up-to-date indexing and searching than previous versions of full-text indexing for Exchange 2003 and Exchange 2000. Full-text indexing and the use of Exchange Search rather than Store Search are now recommended as a Best Practice for all Exchange 2007 mailbox databases.

 

 

Technet

How to Diagnose Exchange Search Issues
https://technet.microsoft.com/en-us/library/bb123701(EXCHG.80).aspx?track=cc_exchange_sync

How to Disable or Enable Exchange Search
https://technet.microsoft.com/en-us/library/aa996416.aspx

How to Rebuild the Full-Text Index Catalog
https://technet.microsoft.com/en-us/library/aa995966(EXCHG.80).aspx

How To Use Exchange Search to Locate Messages for the Purposes of Review or Deletion
https://technet.microsoft.com/en-us/library/aa997688.aspx

Indexing Exchange Server 2007 Public Folders
https://blogs.msdn.com/enterprisesearch/archive/2008/06/06/indexing-exchange-server-2007-public-folders.aspx

Managing Exchange Search
https://technet.microsoft.com/en-us/library/aa998289.aspx

Understanding Client Throttling
https://technet.microsoft.com/en-us/library/cc540454.aspx

Understanding Exchange Search
https://technet.microsoft.com/en-us/library/bb232132(EXCHG.80).aspx

How To Use Exchange Search to Locate Messages for the Purposes of Review or Deletion
https://technet.microsoft.com/en-us/library/aa997688.aspx

 

Microsoft Exchange Team Blog and Team Wiki

Exchange Search FAQ
https://www.exchangeninjas.com/ExchangeSearchFAQ

Exchange Server 2007 Cross Mailbox Search using Export-mailbox
https://msexchangeteam.com/archive/2006/12/18/431934.aspx

The new Search in Exchange Server 2007
https://msexchangeteam.com/archive/2006/10/11/429163.aspx

 

KB Articles

944516  How to register Filter Pack IFilters with Exchange Server 2007
https://support.microsoft.com/default.aspx?scid=kb;EN-US;944516

945077 The Outlook Web Access search function does not work for some users in Exchange 2007
https://support.microsoft.com/default.aspx?scid=kb;EN-US;945077

 

Office Online

Can I remove the Instant Search pane?
https://office.microsoft.com/en-us/outlook/HA102388301033.aspx

Chapter 11: Searching Outlook Data
https://msdn.microsoft.com/en-us/library/cc513841.aspx

Create a Search Folder
https://office.microsoft.com/en-us/outlook/HA100389111033.aspx

Enable or disable Instant Search
https://office.microsoft.com/en-us/outlook/HA102378331033.aspx

Find a message or item by using Instant Search
https://office.microsoft.com/en-us/outlook/HA012305851033.aspx

Find and organize messages with Search Folders
https://office.microsoft.com/en-us/outlook/HA102341231033.aspx

Instant Search is not finding items
https://office.microsoft.com/en-us/outlook/HA101980851033.aspx

Learn to narrow your search criteria for better searches in Outlook
https://office.microsoft.com/en-us/outlook/HA102388311033.aspx

Reset indexing by rebuilding your Instant Search catalog
https://office.microsoft.com/en-us/outlook/HA102378321033.aspx

Turn off the prompt for installing Windows Desktop Search
https://office.microsoft.com/en-us/outlook/HA102429341033.aspx

Use Search Folders to gather messages marked as Important
https://office.microsoft.com/en-us/outlook/HA012305791033.aspx

 

Advanced Query Syntax

Chapter 11: Searching Outlook Data
https://msdn.microsoft.com/en-us/library/cc513841.aspx

Advanced Query Syntax
https://msdn.microsoft.com/en-us/library/aa965711.aspx

Advanced Query Syntax
https://msdn.microsoft.com/en-us/library/Bb266512(VS.85).aspx

Windows Search Advanced Query Syntax
https://www.microsoft.com/windows/products/winfamily/desktopsearch/technicalresources/advquery.mspx

New Mansions in Search - Advanced Query Syntax
https://blogs.msdn.com/jonasbar/archive/2007/01/31/new-mansions-in-search-advanced-query-syntax.aspx

Advanced Query Syntax: What, Where, Why, and How
https://blogs.msdn.com/cheller/archive/2006/12/05/advanced-query-syntax-what-where-why-and-how.aspx

 

Group Policy for Windows Search
https://technet.microsoft.com/en-us/library/cc732491.aspx

Windows Desktop Search 3.01 Administration Guide
https://www.microsoft.com/downloads/details.aspx?FamilyID=00645e54-70a8-4d05-906d-af8773cbc728&DisplayLang=en

Windows Search 4.0 Administrator's Guide
https://technet.microsoft.com/en-us/library/cc772446.aspx

Windows Search
https://msdn.microsoft.com/en-us/library/aa965362(VS.85).aspx

Windows Search 4.0
https://www.microsoft.com/windows/products/winfamily/desktopsearch/choose/windowssearch4.mspx

Windows Search: Technical Resources Overview
https://www.microsoft.com/windows/products/winfamily/desktopsearch/technicalresources.mspx

Description of Windows Desktop Search 3.01 and the Multilingual User Interface Pack for Windows Desktop Search 3.01
https://support.microsoft.com/kb/917013

Bob Want, Senior Support Escalation Engineer, Enterprise Communications Services, Microsoft
Jack French, Senior Support Escalation Engineer, Enterprise Communications Services, Microsoft