This document addresses these issues and provides configuration procedures necessary to connect your Small Business Server to the Internet.

Configuring SBS to work with existing ISPs

If you already have a connection to an ISP that you would like to maintain, there are several issues to consider. If your ISP is supporting Small Business Server for new customers, it may be easiest to have them provide you with a signup diskette that will configure your server and allow you to maintain your existing relationship.

The primary functions that Small Business Server compliant ISP's provide are:

• Electronic mail routing and queuing
• Internet access for your desktop PC's
• Web hosting with FrontPage extensions

Your existing ISP may provide some or all of these functions. The following sections outline the various types of accounts and what is recommended in each case.

Dial-up Accounts

Dial-up accounts, such as those provided by companies like AOL, MSN and CompuServe, are used in small businesses primarily to send and receive mail on an individual basis. While this does provide a way for small businesses to use Internet e-mail, it requires everyone who wants an individual mailbox to have a separate account. Small Business Server provides a much richer solution. By using Exchange Server, small businesses will have a full mail solution for the entire company using a single ISP account and a single phone line. For small businesses with dial-up accounts, we therefore recommend moving to an ISP that supports Small Business Server (for example, one that supports the queuing of mail, Web hosting and dial-up connectivity for Proxy Server). Customers can set up an account with an eligible ISP through the Internet Connection Wizard or through another supported configuration process.

It should be noted that the small business can choose to retain their individual accounts if need be (for example, if they are printed on business cards, and so on), or they can slowly migrate mail being sent to those accounts over to the Small Business Server account.

Web Hosting Services

A small business may already have a relationship with an ISP who is hosting their Internet Web Pages. While the small business does gain an Internet presence through this relationship, they do not achieve an integrated Web posting solution, and they may or may not receive Internet connectivity. For small businesses in this situation, we recommend that they seek out an ISP that fully supports Small Business Server. This will provide them with the complete e-mail and Internet solution. If they wish to keep their existing ISP for Web Hosting, and the ISP supports Web posting via ftp, the small business can configure Web Posting on Small Business Server to use their ISP, as outlined below.

Exchange Dial-up Mail

There are some ISPs that support the dial-up connection of an SMTP server such as Exchange. If this is the case, the small business already has an Exchange Server and an ISP. The small business will want to make sure that their current ISP fully supports the other Small Business Server features as well (for example, Web hosting and dial-up connectivity for Proxy). After the small business installs Small Business Server, they will have to configure Exchange, Proxy, and Web Posting as outlined in the section below.

Full-Time Connection

The small business may already have a full-time connection to their ISP through a modem or leased line. If this is the case, the small business will have to make sure that the ISP fully supports Small Business Server and then configure Exchange, Proxy, and Web Posting as outlined in the sections below.

What you will need from your ISP

Connection Information

This section assumes that you will be using a modem to connect to the ISP. This document also covers the configuration requirements of dedicated or high-bandwidth connections later. For dial-up connections, you will need:

• A dial-in phone number for the modem connection
• A User-ID and password to authenticate your connection
• An IP address (dynamic IP addresses are covered in the electronic mail section)
• Dial-up networking configuration information (optional)

DNS Configuration

To communicate on the Internet, a company needs an Internet domain name. It identifies the location of the network server and is part of the company's Internet e-mail address (user@InternetDomainName.com) or its URL for a Web site (www.InternetDomainName.com).

There are two levels of Internet domain names between which a company can choose:

• Second-level. A second-level Internet domain name contains the name by which you choose to be known. Such as @YourCompanyname.com.
• Third-level. A third-level Internet domain name contains the ISP name in addition to the name by which you choose to be known. Such as @YourCompanyname.ISPcompany.com.

Registering a Second-Level Domain Name

To register a second-level domain, all the small business needs to do is run the Domain Name Registration Wizard from the Manage Internet Access page in the Small Business Server console. This wizard executes all of the necessary commands to ensure that e-mail is delivered to the correct accounts and that Web posting and hosting works correctly. (Note: Your ISP must support the creation and use of second-level domain names for the wizard to complete the task.)

Configuring Small Business Server to Use an Existing Second-Level Domain

A small business may already have the rights to a second-level domain name and want to configure Small Business Server to work with this domain name. To do this, the small business will have to change any third-level domain name entries to the second-level domain name.

ISP Tasks

Your ISP will need to configure several entries in their DNS.

For e-mail, there should be two DNS MX (Mail eXchanger) records for your domain and a DNS A (Address) record for your host. One MX record points to your Small Business Server, and the other points to the ISP's mail host. So DNS excerpts look like:

yourdomain.com	IN	MX	10	yourserver.yourdomain.com
yourdomain.com	IN	MX	20	ISPserver.isp.com
yourserver.yourdomain.com	IN	A	x.x.x.x

The ISP should also configure a reverse lookup entry for yourserver.yourcorp.com (a PTR record).

x.x.x.x

IN

PTR

yourserver.yourdomain.com.

In addition, you will need the IP address of the ISP's DNS server for your server configuration

Electronic Mail Information

In addition to the DNS entries above, you will also need to know the DNS name and IP address of the ISP's mail host. In some cases, the ISP may have separate hosts for inbound and outbound mail. To configure your Exchange Server, you will need the DNS name and IP address of both hosts.

Web Hosting Information (optional)

Small Business Server includes Microsoft FrontPage for web site creation and maintenance. In addition, the Web Posting Wizard is provided to help publish content you create to the ISP system hosting your web site. To take advantage of these features, the ISP needs to support FrontPage extensions and the Web Posting Wizard. The Web Post control on the SBS Console uses FTP to publish your web content. The ISP will need to provide you an FTP address that corresponds to the location of your web content and a userid/password for that FTP location.

If your web site URL is http://www.yourcompany.isp.com/, the FTP location may look like "ftp://www.yourcompany.isp.com/www"

More documentation on web publishing can be found at http://www.microsoft.com/windows/software/webpost/

Configuring your server

You will need a Dial-Up Networking Phonebook entry for your ISP. Open the Dial-Up Networking folder from Start\Programs\Accessories\Dial-Up Networking and select "New". (If this is the first time you have run Dial-Up Networking, the wizard will automatically start).

You will also need to configure your DNS domain name. Click the Start Button and choose Settings, then Control Panel. Double-click the Network Properties icon and select the Protocols tab. Select TCP/IP and click the Properties button to bring up the protocol properties. Select the DNS tab and enter your domain name (e.g. yourcompany.com)

Configuring Proxy

To configure Proxy Server to connect to the right ISP account for Web browsing, perform the following steps:

For a Full-Time Connection:

1. On the desktop, choose the Start button, select Programs, Microsoft Proxy Server, and then point to Auto Dial Configuration.

On the Dialing Hours tab, ensure that Enable Dial on Demand is not selected.

For a Dial-Up Connection:

1. Create a RAS phonebook entry for the ISP account that you need. This is done through double-clicking My Computer and then Dial-Up Networking and selecting New.
2. Click Start, and then select Programs, then Microsoft Proxy Server, and then Auto Dial Configuration.
3. On the Credentials tab, select the RAS phone book entry that you just created and fill in the appropriate username and password to connect with (this will be provided by the ISP). Depending on your ISP's configuration, there may not be a value for the "Domain" field.

   

Configuring Web post wizard

The Web Posting Wizard on the Small Business Server Console uses FTP to publish your web content. If your ISP supports this method of content publishing, you will need to manually configure your server with the necessary information. The Web Posting Wizard requires a registry entry to be created containing the FTP address of your web content. To launch the registry editor, click the Start button, choose Run, enter regedt32.exe and press OK. Select the window titled "Local Machine on Local Machine". The full path is shown in the status bar of the Registry Editor (HLKM is short for HKEY_LOCAL_MACHINE). Create the following keys:

HKLM\Software\Microsoft\Small Business\Internet
HKLM\Software\Microsoft\Small Business\Internet\WEB_INFO

In the WEB_INFO folder, create the values:

FTP_PATH (REG_SZ)= ftp://webftproot
InternetSite (REG_SZ)= http://www.yourcompany.isp.com
Name (REG_SZ)= "publishing account ID"
Password (REG_SZ)= "publishing account password"

Warning Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

Configuring Exchange

When you install Small Business Server, Exchange Server is installed and the Internet Mail Service (IMS) connector created. What remains is the configuration of the connector to receive and deliver your mail. Launch the Exchange Administration program from Start\Program Files\Microsoft Exchange. The Internet Mail Service connector is in the Site\Configuration\Connections container. Double click the connector, or select File\Properties to configure the IMS.

1. Configure the Internet Mail page

   To set the administrator mailbox, click on the Change button and select the name of the user who will be responsible for receiving alerts and notifications.

2. Configure the Address Space page

   Create a new Internet Address Space with an Email Domain of "*" (no quotes) and a cost of "1"

   Configure the Dial-Up Connections page

   1. Select the schedule you want
   2. Set the "Mail Retrieval" option. If your ISP supports ETRN, choose "ETRN Delivery"

   Configure the Connections page

   1. Set "Forward all mail to host:" to the IP address of the ISP mail host
   2. Select "Dial Using" and choose your RAS/DUN phonebook entry

3. Configure the Routing page

   Disable message Routing

4. Configure the Site\Configuration\Site Addressing properties

   On the Site Addressing tab, check the setting of the SMTP address. It should be set to your company's DNS domain name (e.g. "@yourcompany.com" or "@yourcompany.isp.com"). If you change the setting, you will be asked if Exchange should start a background job to update all the mail recipients with the new address – choose Yes.

5. Set the Internet Mail Service to Automatic startup. Click the Start button and choose Settings, then Control Panel. In Control Panel, double-click Services. Select the service titled "Microsoft Exchange Internet Mail Service, press Startup and set the Startup Type to Automatic.

Issues with Dynamic IP addressing

Typically, SMTP mail delivery requires a fixed, or dedicated, IP address. This is due to the mechanisms used to route and deliver mail on the Internet. SMTP mail relies on DNS MX (Mail eXchanger) records to direct mail for a domain (the part of the address to the right of the "@" sign) to a destination. The Internet standards for mail require that the MX record point to a host name that has a DNS A (Address) record. The A record maps the host name to an IP address. The configuration above relies on the ISP allocating a fixed IP address to your Dial-Up Networking session. Essentially, having a fixed IP address means that every time you dial your ISP you will have the same IP address for your server.

While it is possible for the ISP to devise a solution to this issue, it has been very uncommon. The NT based solution recommended by Microsoft to Small Business Server referral ISP's, however, takes advantage of some unique features of NT to allow dynamically addressed systems to receive SMTP mail delivery. When a customer signs up with an SBS ISP, a unique ID is generated and stored in the registry of the SBS server. When Exchange connects to the ISP for mail delivery, it uses the unique ID to generate a WINS record for itself on the ISP WINS server. Then the software issues an SMTP ETRN directive to the ISP mail queue server (an Exchange server), waits for the mail delivery to begin, then deletes the WINS record. Since the NT DNS server can resolve host names from WINS, no DNS A record is required on the server and the WINS record is updated with the correct IP address each time the SBS server connects.

Unless your ISP is unusually creative, the reasonable solutions to this dilemma are a fixed IP address, or an SBS compliant ISP.

Configuring SBS to work with non-dialup connections

The Small Business Server Internet Connection Wizard was designed to assist first time users find an ISP, sign up for an account, and configure the SBS system. For higher levels of service such as dial-on demand router, frame-relay, and T-1 connections, there are both some manual configuration tasks to perform, and some optimizations you can take advantage of. The various types of connections are discussed first, with application issues to follow.

ISDN connections

ISDN is a special case because it depends upon the type of hardware you purchase. ISDN devices are available as ISA or PCI cards to be installed inside the computer just like an internal modem. These are typically called "ISDN Terminal Adapters" or "ISDN modems". ISDN devices are also available as external devices, often called "dial-on demand routers". Both the internal and external devices can be operated in two modes – dial-up and dedicated. Dial-up is much more common because of the cost advantage. In a dedicated configuration, the line is "up" all the time and has the same characteristics of the Leased Line solutions below with bandwidth of either 64Kb or 128Kb.

ISDN TA's

Internal ISDN adapter cards are available from several vendors with a variety of features. Some are installed as network cards through Control Panel\Network, and others as modems. They all use a DUN Phonebook entry to connect to the ISP like an internal modem though.

ISDN Routers

ISDN Routers are often used in a "dial-on demand" configuration. This is possible because the call setup times for ISDN are extremely fast as compared to standard analog modems (2-3 seconds vs. 20-30 seconds). In this configuration, the SBS server is configured with two network interface cards (NIC's) – one for the internal network, and one for the external network that connects to the ISDN Router. Whenever there is outbound traffic from the SBS server, the router automatically raises the connection to the ISP. To the clients on the SBS network and the SBS server itself, it appears as if there is a full time connection. What is special about this case is that from the perspective of the ISP hosts, it appears as if there is a normal dial-up connection. There are some special configuration considerations for Exchange Server noted below.

ISDN Mode Matrix

Leased Line connections

Leased line connections typically range from 56Kb to T-1 (1.544Mb) lines. The common feature is that they are all "dedicated" connections, available all the time. Again, as with dedicated modems or ISDN lines, there are some special configuration issues – primarily with Exchange Server. Leased Line connections all require a Router for operation. The SBS server is configured with two NIC's for these connections as well – on e for the internal LAN, and one for the External connection with the leased line router.

Configuring NT

If you choose an external ISDN or Leased Line solution, there are some points to consider when setting up the Small Business Server for Internet connectivity.

• You will need to add and configure the second network card via Control Panel\Network applet. Your ISP will need to provide you fixed IP addresses for both the router and the external NIC in the SBS server.
• You will not be able to use the Internet Connection Wizard to set up your account

Configuring Proxy

In the dial-on demand and dedicated connection configurations, you will not be using Dial-Up Networking, so Proxy server does not need to be configured for "Autodial". You will need to configure the Local Address Table (LAT) on the Proxy server to differentiate the internal and external networks.

Configuring the Web Post Wizard

There are no differences in the Web Post Wizard configuration from that described in the previous section.

Configuring Exchange

The ranges of high-speed connections present two scenarios for configuring the Exchange Server.

Scenario 1: Dial-on Demand or Dial-up Networking

The basic configuration is the same as the steps above with the exception of Step 3, which is eliminated, and Step 4, where no Dial-Up Connection is set.

In this scenario, the Exchange Server can always send outbound mail immediately, but the line must be brought up to receive mail. While the line is down, mail will be queued on your ISP's mail host. Exchange and most ISP's now support the SMTP extension, defined in RFC1985, called ETRN.

In Exchange 5.0, the only way to send an ETRN to your ISP's mail host, when you are not using the Dial-Up Connections features, is with an external program. One example of such a program is available from the Simpler-Webb web site ( http://www.swinc.com/resource/exch_dq.htm ). You will need to schedule the program with AT, WINAT (reskit), CROND (shareware), or another scheduling package.

Exchange 5.5 has added a new registry key to force the IMS to send an ETRN whenever it connects to deliver outbound mail. The one requirement here is that you use the "Forward all mail to:" option for your outbound mail. This will be the server to which Exchange sends the ETRN to trigger the mail delivery.

The key is a DWORD with possible values of 0 and 1 (off - don't send, and on - send, respectively).

HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIMC\Parameters\AlwaysUseETRN

This will cause mail to be dequeued from the ISP every time outbound mail is sent from your system. This may be less regular than is acceptable for your inbound mail requirements, so you may need to force the issue. You can schedule the delivery of a dummy mail message at the frequency that you desire. One alternative is to use a Link Monitor to generate the test message. Another alternative is to use AT, WINAT (reskit), CROND (shareware), or another scheduling package to run a command line utility to send the mail message.

If your ISP does not support ETRN, both you and the ISP should visit http://www.swinc.com/resource/exch_dq.htm and select a mutually agreeable dequeing method.

Scenario 2: Leased Line or dedicated connection

The basic configuration is the same as the steps above with the exception of Steps 3 and 4, which can both be eliminated.

In this scenario, the Exchange Server can always send outbound mail immediately, and receive inbound mail immediately.

Differences between POP Mail and SBS Exchange Mail

POP Mail

POP is an acronym for Post Office Protocol. The most widely used implementation of this protocol is version three, or POP3. POP3 is a retrieval protocol. Simply put, it is used to retrieve mail messages from a POP server. In other words email messages that are received by the POP server are delivered to a mailbox on the server, and reside there until an individual who has a POP mail client retrieves them.

Depending on the POP mail client that is used, a user can choose to:

• Download all of the messages that are queued on the POP server and remove the messages from the server.
• Download all messages or all new messages and then leave a copy on the POP server.
• Download just the message headers and then mark the messages that they wish to download. (This feature is not found in all POP mail clients)

Because POP3 is a messaging protocol designed for retrieval only, it must work in conjunction with a protocol that is capable of sending messages. The SMTP protocol is used by POP clients for sending outbound mail.

SMTP

The acronym SMTP stands for "Simple Mail Transfer Protocol." It is the standard protocol for mail transfer over the Internet. SMTP defines how a message will be formatted for delivery, as well as provides the mechanism for delivery over connection based protocols such as TCP/IP (Transmission Control Protocol/Internet Protocol). The Exchange Server Internet Mail Service uses SMTP to send and receive mail. In addition, POP clients use SMTP to send messages to SMTP hosts for routing and delivery over the Internet.

Differences between POP and SMTP

The POP3 protocol is only capable of retrieving mail from a POP3 host, and thus is dependent on the SMTP protocol to deliver outbound messages. The SMTP protocol is a more robust transport protocol capable of two-way communication with other SMTP hosts.

The Benefits of using an SMTP server

Included in the suite of applications for BackOffice Small Business Server is Microsoft Exchange Server. Microsoft Exchange Server is a server application that provides not only messaging capabilities between users on a local network, but is also capable of providing messaging capabilities over the Internet.

The version of Microsoft Exchange that is included with Small Business Server comes with an "Internet Mail Service." This Internet Mail Service uses the SMTP protocol to send and receive messages over the Internet, making it an SMTP server. The advantages of using an SMTP server over a POP mail client are many:

POP mail client

• Messages are not received in real time
• Messages cannot be viewed from multiple clients after download
• Storage increase due to multiple message copies stored by each recipient
• On-line backups are difficult to perform
• No transactional integrity of the message store (client side files)
• ISP POP accounts require additional UserID and Password maintenance

Exchange Client

• Messages are received in real time.
• Messages are accessible from any local or remote client
• Single instance storage of messages addressed to multiple recipients
• On-line backups and transactional integrity of message flow
• Message size limits can be imposed.
• Can access Exchange Public Folders
• More Robust Offline working capabilities
• Server based rules, which can dictate how a message is handled when the server receives it.
• Security is integrated with Small Business Server security

Where can I go for more information?

There are several good sources for more information for both the ISP and the SBS customer:

The Microsoft SBS Web Site:
http://www.microsoft.com/backofficesmallbiz/default.asp

The Microsoft SBS ISP Resource Kit home page:
http://irpcomm.microsoft.com/sbs/ispkit/Default.htm

The Microsoft's Exchange Internet Connectivity white paper:
http://www.microsoft.com/exchange/guide/papers/connecttointernet.asp

Simpler-Webb, Inc.'s Exchange and SMTP Web Site:
http://www.swinc.com/resource/exch_smtp.htm

Birk Binnard's SBS Info Web Site:
http://www.birkbinnard.com/sbs