Outlook sucks. It won't allow me to delete more than 4000 items at a time. I still have over 86,000 to delete, starting with over 105,000. This will take me forever.

UPDATE: Maybe using the Archive option might be a good idea. Let Outlook archive everything into a PST then simply delete the PST. I started to try this route then it stopped with a useless error message which didn't help me in the slightest. Trying again!

UPDATE 2: After a ridiculous amount of time spent on deleting all those damn emails I finally completed it yesterday - archiving didn't really work as it kept getting stuck on certain messages for no reason I could figure out, so I ended up doing most of it manually again.