Using Entourage for Mac (2004 or 2008) while connecting to an Exchange 2007 mailbox on a Windows 2008 Server, user cannot download any e-mail message which has a plus sign in the subject line, like ‘Mail + Issue’.
Entourage’s request to download this e-mail message goes thru IIS 7 on Windows 2008 Server, which is configured (by default) to deny ‘double escape sequences’ in any HTTP request and thus it rejects the request with a ‘404.11’ error.
As Entourage talks to ‘Exchange’ virtual directory (for mailbox access) under ‘Default Website’ on IIS, thus you can use the following procedure to allow the use of ‘double escape sequence’ only at that level to address this issue. This will minimize the risk you will be taking to enable the usage of double escape sequence. Enabling the use of ‘double escape sequence’ does carry some risk, please go thru the links below under ‘More Info’ section to get yourself educated on the issue & involved risks before you work on the steps below.
1. Bring up Notepad : File : Open, type %windir%\System32\inetsrv\config\applicationHost.config in the ‘File name’ box, and then click ‘Open’.
2. Locate the section titled as: <location path=”Default Web Site/Exchange”>
3. Under that section locate </authentication> tag
4. Just after that insert the following text on a new line: <requestFiltering allowDoubleEscaping=”true” />
5. Save the file and ‘Exit’ Notepad
No restart of any service is required.
As Entourage talks to ‘Public’ virtual directory (for public folder access) under ‘Default Website’ on IIS, thus you will need to follow the same procedure for ‘Public’ virtual directory as well. Same instructions apply; just replace ‘Exchange’ with ‘Public’ in all steps mentioned above.
This text was found and copied from a blog, don’t remember which one (sorry) and some editing in the text has been done.