I got so fed up with the fixed size of the Outlook Rules dialog that I wrote a batch script to to resize it using cmdow[1]. (I have over 50 rules.)
I got so fed up with Outlook that I surveyed the bigger half of the office population to find out the outbound server and switched to Thunderbird under a linux vm. Not sure whether it helped with the keyhole problem tho.
Thunderbird is by far the best MUA I've used. I use a Chromebook as my daily workstation and I cannot wait for it to support Linux applications so I can run Thunderbird rather than my current situation (a mix of web-mail and ALPINE).
I don't own a chromebook, but have you tried [0]? Looks like it allows to run linux programs fairly easily.