When accessing your email using Outlook Web Access on an Exchange 2003 mail server, you find you are unable to compose or reply to a message. Instead of being able to place your cursor in the body of the email message, you see a square with a red “x” in the body of the message.
This problem can occur as a result of a security update applied to the Exchange 2003 Server. The workstation attempting to access Outlook Webmail does not have the current security update applied.
To resolve this issue:
Connect to your Outlook Web Access (OWA)
From your OWA, click on the “options” in the left Task Pane.
In the right hand frame, under the ‘E-mail Security’ option, select ‘Download’ to install or upgrade the S/MIME Control. This will download the S/MIME add-on.
After installing the security update you may be presented with the notification: ‘This website wants to run the following add-on: Microsoft (R) Dynamic HTML Editing Control’.
Right click on the notification and select ‘Run Add-on’ to activate the control
Implementing Outlook Web Access with the S/MIME Control
How to Install the Outlook Web Access S/MIME Control
Configure Message Security in OWA 2003