Tired of Outlook Web Access blocking that attachment you would need most urgently, just because it has some weird extension?? Fear not, for this behaviour is customizable.

Fire up regedit on your OWA Server, and head for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA

It should look pretty much like the screenshot here: 

Here you can see the 2 keys of interest: Level1FileTypes and Level2FileTypes.

Level1FileTypes: These files can not be accessed via OWA in any way - you can not view/download them, heck - you can not even click them.

Level2FileTypes: These files can not be viewed directly with OWA, you have to save them to your PC before you can open them.

So, lets say you want to be able to receive *.mdb-Files, you would just have to remove the mdb-string from Level1FileTypes. Remember, all file extensions are seperated by a comma, and there should be no spaces anywhere in the string.

This behaviour is also document in the MS KB; have a look at http://support.microsoft.com/kb/555001

Have a good one,

Georg