The monitors, I totally understand and agree with. That's about actual productivity. But choosing your own e-mail address? There must be a thousand little details like that in my life, every day, that I have no control over, like the color of my desk, or the sound of a coworker's voice. By all means, try to find a workplace that suits you the best, but if a seemingly tiny detail like that bothers you so much, unless…
If the corporate email system cannot provide service that is as good, then people will start using services like Gmail instead. I see it happen all the time.
Personally I also regard it a sign of cluefulness to have an email address with very short local part. I always hated Gmail's 6-char minimum limit for usernames.