Challenges Implementing Autodiscover

One of our visitors recently asked whether there are any challenges with implementing Auto Discover effectively, and Owen, our resident expert, had this to say:

The simple answer, the setup can be as simple or as complex as your corresponding Exchange environment. In a simple Exchange 2007 scenario, where Exchange routes for only one domain, the setup is fairly straightforward. As part of the Exchange 2007 CAS server installation, the necessary Autodiscover components are installed by default on the CAS server, and corresponding SCP records created in Active Directory. For users connecting from remote systems, such as laptops or home computers, an external DNS record is required which directs requests to autodiscover.yourdomain.com to the external address of the Exchange 2007 CAS server.

For more complex Exchange 2007 implementations, with multiple email domains, many external users, and custom SSL certificates, there are a few issues to overcome. Microsoft recommends that a separate website be created for a heavily utilized Autodiscover service. For multiple email domains, individual DNS records for each email domain need to be directed to one common HTTP based URL, which should to be configured to redirect all requests to an HTTPS enabled CAS server hosting the Autodiscover web site. This allows the use of multiple email domains, but one common Autodiscover site and corresponding SSL certificate. Otherwise, individual Autodiscover websites would need to be created on the CAS server, each with individual SSL certificates, which would become cumbersome and expensive to manage.

As Exchange 2007 has introduced a new web based delivery mechanism for Offline Address Books (OABs) for Outlook 2007 clients, replacing the Public Folder method used for Outlook 2000 through 2003 clients, a fully functioning Autodiscover service is required to maintain full functionality for Outlook 2007 clients. The same is true for Unified Messaging and Availability services, therefore a good understanding of and well designed Autodiscover implementation is key to a successful Exchange 2007 deployment.

For further information, Microsoft has published a good description on their TechNet site that describes the various scenarios, and potential solutions.

Autodiscover in Exchange 2007 and Outlook 2007

Exchange administrators and end users alike will praise the new Exchange 2007 feature known as Autodiscover. This new feature, combined with Outlook 2007, makes the setup of new Outlook profiles as simple as logging into your webmail. Simply provide Outlook your email address and password, and your Outlook profile is configured with no other information required. Gone are the days of needing to know your server name, or hunting for the settings and location to input your RPC over HTTP information.

This feature is elegantly accomplished through external DNS records, and features included on the new Exchange 2007 Client Access Servers (CAS). Administrators simply need to publish a DNS record on the internet for autodiscover.yourdomain.com, directing it to the CAS server of their Exchange email environment. The CAS server then provides the settings to Outlook 2007, including their Exchange server name, their RPC over HTTP settings (now called Outlook Anywhere), their offline address book web URL, their display name, and any other information required. This information is provided through a file called Autodiscover.xml, which is hosted by an IIS website on the CAS server, secured through NTLM authentication and SSL communications.

Similar principles are in place for Outlook 2007 with regards to personal accounts provided through user’s Internet Service Providers or free email providers. Many providers have the required information published that allows a user to simply input their display name, email address, and password, and Outlook 2007 automatically applies the required settings. You no longer need information regarding your incoming mail server, outgoing mail server, authentication settings, etc.

Simply put, Autodiscover makes accessing your email that much easier.

The Exchange database engine

Exchange can be considered to be a special purpose database application. The database is all the email and calendar entries in everybody's mailbox. Rather than writing a database from scratch, Microsoft used the Jet Database engine also used by Microsoft Access. What's that you say, gasping in horror, Microsoft Access is running my corporate email system??? Yup. It also runs your Active Directory, by the way.

Why doesn't Microsoft switch to a "real" database like SQL Server. There's certainly been talk about this for years, and a lot of rumors that would happen in E2K7, but it didn’t go down that way. And here's the rub: Jet is actually way faster than SQL Server.

SQL Server is built from the ground up to be a true multi-client, multi-machine, client-server database, and that carries lots of overhead.

All the clients need to create ASCII "SELECT" statements, send them over a skinny little pipe to the server, have the server parse and execute the queries, and then send the results back over the same skinny pipe to be parsed on the client end and then served up to the application.

By contrast, the Jet data and Jet engine sits right on the same computer as the application accessing the db, and uses big fat shared memory communications. Meanwhile, Exchange has customized and optimized the heck out of it to ensure the database performance is super-optimized for Exchange. Because the Exchange store.exe process manages all the communications to the database, there is no need for all the overhead of a true client-server database.

For a true client-server app, there is no substitute for a nice robust relational database like SQL server. But for an app like Exchange where all communications to a given computer are already funneled through a “front-door” process (store.exe), it’s really not necessary… honest…

Outlook or Google mail?

The UK's ITWeek asks whether or not Outlook should be consigned to the scrap heap and replaced with Google mail.

This writer makes some interesting points, but we'll wager he hasn't tried Exchange 2007 yet. His primary issues - the fit between Outlook and Exchange 2007 is on our top eleven list, as are the improved Outlook Web Access, and how 2007 addresses expanding mailboxes with a revised architecture - are all addressed in Exchange 2007. As for Google - we'd like to hear from readers who are considering or using Gmail for their businesses - would you go with a service like Gmail for corporate mail? Why or why not?