Alright I’m hooked on this idea, how do I proceed? Well fortunately there exist a couple of solutions on the Internet, the most comprehensive is a 3rd party product called ActiveSend developed by Messageware whom we know from products such as the OWA Plus Pack and SessionGuard. When ActiveSend has been installed you need to enter the URL to your OWA site and  specify the username and password, so that the product doesn’t need to open the OWA Forms-based authentication page or authenticate with a username/password each time you want to send out an email, see figure 1 and 2 below:

Figure 1: ActiveSend Configuration - General

Figure 2: ActiveSend Configuration - Security

ActiveSend integrates OWA with Microsoft Office as well as other MAPI applications so users can easily send attachments from within applications with just the click of the "Send To" button. ActiveSend turns OWA into the default mail client, so users can one click and utilize the Mail To: hyperlinks found in email, documents and web sites (see figures 3, 4, 5 and 6). It can’t get much better than that can it?

Figure 3: ActiveSend – Mail Recipient in Word

Figure 4: ActiveSend – OWA Message through Word

Figure 5: ActiveSend – OWA Message through Context menu

Figure 6: ActiveSend – OWA Message through mailto: Link in Internet Explorer

ActiveSend also replaces the Outlook icon in the Start menu.

As you might have guessed ActiveSend isn’t freeware although the product is priced relatively low ($25 per CAL or even lower depending on number of users), therefore if you’re looking for a freeware solution you should instead checkout Exchange MVP Siegfried Weber’s Exchange WebForms package (WebForm NewMail) over at his Playground site. Be aware though this solution is far from perfect compared to the one delivered by Messageware.

To make it possible to select OWA 2003 as the default mail client you only need to execute the OutlookWebAccessAsMailClient.wsf located in the WebForm – NewMail  which is a subfolder to Exchange WebForms, here you simply specify the URL of the OWA server as shown in figure 7:

Figure 7: WebForm NewMail Script

Then you can select OWA as the default mail client under Tools > Internet Options > Programs in Internet Explorer (see figure 8).

Figure 8: Specifying Outlook Web Access as the Default E-mail Program in IE

Note
Siegfried Weber has a ton of other very useful OWA scripts and add-on’s so no matter if you select to checkout his Exchange WebForms package or not his site is definitely worth a visit.

Finally Tosh Meston who’s a developer on the Microsoft OWA team also has some information on making OWA the default mail client by adding a few registry keys to the client, but again this solution is also far from comprehensive compared to ActiveSend.

Blocking Outlook MAPI Client Access to the Exchange Server

Now that you have configured OWA 2003 as the default mail client on your user’s workstations you may want to go one step further and actually block Microsoft Office Outlook (MAPI) access to your Exchange Server as well. This can be done by changing a few settings in the registry; more specifically you need to add a new String Value (REG_SZ) called Disable MAPI Clients under:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

Depending on what Outlook MAPI client versions you want to block, you need to specify the respective version number in the Value Data field of the string value. You can even use a hyphen to block multiple Outlook MAPI versions, for more details see MS KB 288894 - XADM: Feature to Disable MAPI Client Access which has been written for Exchange Server 2000 but also applies to Exchange Server 2003.

Figure 9 shows the Disable MAPI Clients String Value in the registry, in this particular example we block all Outlook MAPI clients newer than the Exchange 4.0 Client meaning we more or less block all Outlook MAPI client access.

Figure 9: Disable MAPI Client Access String Value

Be aware that you need to restart the Information Store service after adding the above string value before the new setting takes effect.

That was all I had to share for now, remember to let me know if you want me to write about a specific topic.