I use Exchange for our personal email. This has worked great for me at work because we've used a POP/IMAP server for my business mail. And even though the company's firewall blocks the POP/IMAP/SMTP ports to the outside world, Exchange will work over https with current versions of Outlook. But, I have an issue. My employer is currently rolling out Exchange. Outlook isn't able to connect to two different Exchange servers in one profile, and isn't able to run more than one profile at the same time (even in two different user contexts if they are in the same window space.)
A quick Google found the Hammer of God site with a program called ExtraOutlook.exe. While interesting (especially the description of how they found out what Outlook was doing) they don't actually say what their app does, which makes me nervous.