Exchange Ideas - 26 Jun 2006

Tips, news, and community resources for messaging admins

Exchange FAQs
Stress-Testing an Exchange 2003 Installation

How can I stress-test my Exchange Server 2003 installation?

The Microsoft Exchange Server 2003 Load Simulator (LoadSim), which you can download from, lets you simulate a number of Messaging API (MAPI) clients' performance loads. After you download the tool, extract and run loadsim.msi. Don't install the tool on the Exchange server; install it on a client that has Microsoft Office Outlook 2003 installed. The download includes a document that describes how to use and monitor the tool.
—John Savill

Using Exchange's SMTP Connector

How can I connect Exchange Server to another mail system that hosts mailboxes for a certain SMTP namespace?

Exchange Server 2003 and Exchange 2000 Server contain several types of connectors. One of them, the SMTP connector, is useful for connecting to other mail systems (including other Exchange organizations) via SMTP. When you configure an Exchange connector, you define an address space (i.e., the email domain's DNS name, such as that restricts which traffic can be sent over the link. Follow these steps to configure the SMTP connector:

  1. Start Exchange System Manager (ESM) by clicking Start, Programs, Microsoft Exchange, System Manager.
  2. Expand Administrative Groups, then expand Routing Groups until you see the Connectors branch.
  3. Right-click Connectors and select New, SMTP Connector.
  4. Enter a descriptive name for the connector in the Name field (e.g., Exchange to widgets.test mail), as Figure 1, shows. Select Forward all mail through this connector to the following smart hosts, and in the text box, enter the other mail system's DNS name or IP address. If you enter the IP address, place it in square brackets (e.g., \[\]). Under Local bridgeheads, click Add.
  5. Select the Address Space tab and click Add. In the resulting dialog box, select the address type (in this case, SMTP) and click OK. Enter the email domain (e.g., *.widget.test), and enter a cost between 1 and 100. (The lower the cost, the higher the link's precedence.)

    If you want this connector to be available to the entire organization, select Entire organization under Connector Scope. Then, select the Allow messages to be relayed to these domains check box.
  6. Navigate through the other tabs for options that might apply to your environment, then click OK.

—John Savill

Unified Messaging in Exchange 2007
For a number of reasons, I've been spending a lot of time digging into the guts of Exchange Server 2007's Unified Messaging (UM) server role. First, I think UM includes an interesting set of technologies that, for the most part, haven't been available to most Exchange sites. Second, Microsoft hasn't publicly said much about how UM works, and the best way to get experience with a technology is to play with it. Third, I'm eager to deploy it at my office because I could really benefit from some of the planned UM feature set. All this digging has been rewarding; I've learned a lot about how Exchange 2007 implements its UM role, what UM can and can't do, and how it all works.

The first thing you should know is that in Exchange 2007, the UM server role implements the UM service set and delivers several key services:

  • It links the physical telephone system (including internal phone lines and trunks that connect to the Public Switched Telephone Network—PSTN) to the Exchange infrastructure.
  • It applies dial plans, which are sets of rules that control who can use voicemail and what those users can do with it. (The term "dial plans" comes from the telephony world; you'll see some other "phone guy" lingo in the UM documentation that ships with Exchange.)
  • It answers telephone calls that are directed to its extension (or pilot number). When a call is delivered to the pilot number, the UM server uses the extension information that the private branch exchange (PBX—or gateway) provides to look up the user's email address, which the server uses to find the user's mailbox and retrieve the greeting message. After the caller leaves a message, the UM server sends it to the mailbox server.
  • It provides an Automated Attendant service that answers internal and external phone calls and automates dialing through directory integration with the Global Address List (GAL), acting as a highly advanced switchboard-type application. You can use the Automated Attendant to directly answer all incoming phone calls, or you can restrict its use to callers within your internal telephone system.
  • It runs Outlook Voice Access (OVA), which uses speech or Touch-Tone (dual-tone multifrequency—DTMF) recognition to provide telephone-based access to Inbox data. OVA also offers text-to-speech functionality for reading email and calendar information back to the caller. This extremely cool feature gives you on-demand access to all your email and calendar data from any telephone.

Of course, the UM server isn't the only component that makes all this magic happen. The PBX that provides your regular switchboard services still establishes calls between extensions and accepts inbound calls; when a call to a given extension goes unanswered, the PBX can transfer it to the UM server's pilot number, and the magic begins. This functionality suggests that your PBX has some way to communicate with the Exchange UM server; the means of communication varies according to what kind of PBX you have. Some PBXs directly support Session Initiation Protocol (SIP), which enables call setup, and Real Time Protocol (RTP), which actually carries voice data. These types of PBXs are commonly referred to as IP-PBXs, and they can directly communicate with the Exchange 2007 Unified Messaging role. Other PBXs don't speak SIP and RTP; these PBX systems require the use of a gateway that translates between the native PBX protocols and SIP and RTP. Microsoft doesn't provide these gateways, but third parties do.

When a voicemail message arrives in your Inbox, the real fun begins. Voicemail messages appear as ordinary messages; however, in Microsoft Office Outlook 2007 and Microsoft Outlook Web Access (OWA) 2007, they have a special icon. The UM server attempts to resolve the caller's telephone number in Active Directory (AD) to match the number with a name. If you're using Outlook 2007 or OWA 2007, you can play the message on your telephone; with any client, you can open the voicemail attachment and play it on the computer. Interestingly, you can also receive and play voicemail messages on Windows Mobile devices. Combine that functionality with Messaging and Security Feature Pack push mail, and you have a nifty solution to help you stay in touch when you want to.

—Paul Robichaux


Follow these links to access the resources mentioned in this month’s Exchange Ideas.

Exchange FAQs
Stress-Testing an Exchange 2003 Installation
”How can I stress test my Microsoft Exchange Server 2003 installation?” John Savill’s FAQ for
Windows, InstantDoc ID 50374

Using Exchange’s SMTP Connector
“How can I connect Microsoft Exchange Server to another mail system that hosts mailboxes for
a certain SMTP namespace?” John Savill’s FAQ for Windows, InstantDoc ID 50372

Unified Messaging in Exchange 2007
“Digging Into Exchange UM,” InstantDoc ID 50363

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