There have been many times in the past when I have started a project for a new customer and discovered that they are not using SSL for their email servers.  Usually after a brief discussion they agree to implement SSL in the new system we are installing for them.

Occasionally they agree but insist on doing it in a less than ideal manner.  And sometimes, although rarely, they decline our advice and continue without SSL.

What is SSL?

SSL stands for Secure Socket Layer and is an encryption protocol that secures communications between two parties over insecure networks such as the internet.  Although still commonly referred to as SSL its new name is actually TLS (Transport Layer Security) which more accurately describes its role of securing communications at the Transport layer of the OSI model (eg, the TCP protocol).

In an SSL/TLS secured communication the two parties (e.g. a web server and a web browser) agree on how to secure the connection they are establishing. Continue reading The Importance of SSL for Exchange Servers

Some Exchange Server 2007 and Exchange Server 2010 roles require Internet Information Services (IIS) to function.   On these servers Exchange will install a series of IIS virtual directories.  In this post I will describe the Exchange Server virtual directories and their purpose.

/owa – This is the directory for OWA (Outlook Web Access on Exchange 2007, and now called Outlook Web App on Exchange 2010), which is the web browser version of Outlook that is usually accessed by remote workers.  The /owa directory is for access to Exchange 2007 or 2010 mailboxes.

/Public – This is the directory used by OWA users when accessing any Public Folders in the organization.

/Exchweb – This directory is used for OWA access for Exchange 2003 or 2000 users but is not usually accessed directly by the end user.  The OWA session will automatically refer the connect to this virtual directory when necessary.

/Exchange – This directory is again used for OWA access.  When an Exchange 2003 or 2000 mailbox user access the /Exchange virtual directory they are proxied to their mailbox.  For Exchange 2007 or 2010 mailbox users they are redirected to the /owa directory for their mailbox access.

This is useful during the transition from legacy Exchange versions to 2007 or 2010, because users can continue to connect to the /Exchange directory and the result will always be that they connect to their mailbox, as long as the server does not run the Mailbox Server role.  In other words, the /Exchange directory only works for legacy mailbox users if the server is a dedicated Client Access Server (though it can also contain the Hub Transport Server role without a problem). Continue reading Overview of Exchange Server Virtual Directories