Microsoft Outlook Express

Outlook Express, shown in Figure 17-3, is a subset of the standard Outlook product. It ships and installs with Microsoft Internet Explorer and is the default e-mail reader for all versions of Microsoft Windows without Outlook or other e-mail client installed. It allows users to retrieve and send e-mail messages, participate in Internet newsgroups, and access directory information over standard Internet-based protocols. Outlook Express cannot take advantage of most of the collaboration features that Exchange Server 2003 provides, such as native access to public folders and calendaring. Let’s look at its three main capabilities—messaging, news reading, and directory service lookup—and see how they differ from their counterparts in Outlook.

Figure 17-3: Outlook Express.

Messaging

E-mail support within Outlook Express is similar to that of the Internet Mail Only option in Outlook: only messaging over the HTTP, POP3, IMAP4, and SMTP protocols is supported. When Outlook Express interacts with Exchange Server 2003 for retrieving messages, it does so over either the POP3 or IMAP4 protocol. This means that although Outlook Express can use Exchange Server 2003 as its messaging server, Outlook Express is not a native Exchange 2003 client. In addition, using Outlook Express to access an Exchange 2003 mailbox does not provide the groupware messaging present in Outlook, such as native access to public folders and Outlook forms.

Outlook Express provides support for multiple e-mail accounts, letting users retrieve messages from multiple servers and view them all in a single Inbox. It also allows multiple users to have their own individual identities for messages, contacts, and tasks. Some basic rules functionality (Figure 17-4) is available through the Create Rule From Message command on the Messages menu. Outlook Express can impose some client-side rules for handling incoming e-mail, but you cannot use it to create server-side rules, as you can with the Rules Wizard in the full Outlook 2003 product.

Figure 17-4: Creating a rule in Outlook Express 6.

News Reading

Outlook Express can act as a news reader for Internet newsgroups via any NNTP-compliant news server, such as Exchange Server 2003. It can access Exchange 2003 public folders as newsgroups over NNTP. However, when using Outlook Express to access Exchange 2003 public folders, you need to consider the client application that created the entry in the public folder. If the entry was created by an NNTP-compliant news reader such as Outlook Express, all contents of the entry are available to Outlook Express. If, however, the entry was created by a native Exchange client such as Outlook 2003, access to that entry with Outlook Express (and with any other NNTP-compliant news reader) is really effective only with public folders containing standard post items (using the IM.Post form). When Outlook Express accesses a public folder as a newsgroup containing any other Exchange message type (contact item, calendar item, journal item, or task item), it shows only the name of the entry and the information found in the notes portion at the bottom of all Outlook message types.

Performing Directory Service Lookups

Many companies on the Internet provide information about various Internet users. For instance, if you wanted to find out the e-mail address of John Smith, you could query various directory service providers to see whether they had any record of his e-mail address or other information about him. Outlook Express makes the directory service queries via Lightweight Directory Access Protocol (LDAP).

Outlook Express does not access LDAP-based information by querying an Exchange 2003 server specifically. Because Exchange Server 2003 relies heavily on Active Directory, to seek information about a user, an LDAP query would be directed to Active Directory via LDAP over TCP port 389. The client could be configured to present any LDAP queries to an Exchange 2003 server or to any domain controller in Active Directory. For more information about LDAP, POP3, IMAP 4, and NNTP, see Chapter 20.