“The cause of the problem is due to Internet Explorer 7 in Windows Vista no longer include support for Dynamic HTML Editing ActiveX control, and thus missing a functionality that Microsoft Exchange Outlook Web Access relies on to do HTML editing in Outlook Web Access.”
You may find yourself unable to compose a new message when trying to access your exchange server via Microsoft Outlook Web Access while using Internet Explorer 7. However, you can access it with Firefox and the Opera Browsers.
If you are having this problem you will see a red square with an “X” in it when you try to compose a new message.
Like this:
The Solution:
1. Slide down the left Task Pane and Click on “options”.
2. Slide down to “E-mail Security” and Click Install or Upgrade the S/MIME Control. This will download a new add-on.
3. Click “RUN” when asked about the Microsoft Outlook Web Access S/MIME install and security warning.
4. Close and RESTART IE7
5. Go back to your Web Access Site (webmail program) and select “New” to begin composing a new message. The program should now be functioning normally and the red “X” should be gone.
ATENTION:
95% of the cases this should work but for that remaining 5% internet explorer might come with an "error on page" message down the bottom in the status bar.
Solution to that error?
Use Mozilla or enter OWA only in basic mode. There are usually 2 options during logon: premium or basic. Basic looks just like in firefox and provides the ability to actually send mails.
Edit:
SSL can fix OWA error on page!
You can solve the problem by using SSL, which you should normally always do when serving OWA in my opinion. This will bypass the IE problem, so you can use the premium client. AND you will get decent security as a bonus.
OWA SSL setup guide at msexchange.org
All the best,
L
p.s. The FIX for a Windows XP (SP1, SP2 or SP3) computers as I have forgotten to mention it above:
On XP, error is caused by two missing registry keys related to the following within the OWA message window.
OBJECT class="MSGBODY" classid="clsid:2D360201-FFF5-11D1-8D03-00A0C959BC0A"
You should have two registry keys - These are probably missing.
HKEY_CLASSES_ROOT\CLSID\{2D360200-FFF5-11D1-8D03-00A0C959BC0A}
HKEY_CLASSES_ROOT\CLSID\{2D360201-FFF5-11D1-8D03-00A0C959BC0A}
These are referenced to two other keys
DHTMLEdit.DHTMLEdit
DHTMLSafe.DHTMLSafe
On a computer that is working with OWA open the registry and search for or navigate to the two keys above. Right click and export the two keys to an USB Memory Stick, Network share etc. On the "broken" PC open the registry and import the two keys. Close IE 7. Reopen IE 7 and OWA should be OK this time.
Apparently this solution works on VISTA Ultimate too. I have not tried this solution on a VISTA machine but if you try it please do let us know the output.
Make sure you back-up you registry first!!!