Not entirely trusting company policies to extend to all employees and situations, I have a slightly more paranoid policy. First off, look at the beginning of the glgarden blurb:

"You may already know that there are many free web based email service providers available, but how do you decide which one of these services is right for you?

One of the things you should consider when making this decision is how anonymous you will be when utilizing these services.

A good reason for not using one of the bigger well known services (such as Hotmail™) is that in general, these services will reveal your originating IP address when sending outgoing emails. "

The revealing of the outgoing IP address isn't a problem if that IP address isn't yours. If you use the email system through a proxy server system such as Tor, the IP addresses all belong to the network. If you NEVER log on to the email under your own IP address, then there is no IP connection to where you are (especially if you use Tor-associated safety features like Privoxy, as well as Firefox add-ons like NoScript and Ghostery to prevent web bug type leakage).

Hotmail at least seems to require an unproxied connection to set up, but that can easily be done at a cash internet cafe in a distant location.

You need to know your Tor (or other proxy server's) vulnerabilities (*http://en.wikipedia.org/wiki/The_Onion_Router#Weaknesses). But don't be fooled by the common statement that Tor blocks port 25, "the email port" (SMTP port). I'm sure it does, but hotmail appears to communicate entirely through port 80, the http port, at least as viewed in my handy map of outgoing port connections, the Tor Network Map's Connection window.

It might be best to turn off the safebrowsing:clients:google function in firefox (go to Tools->Options->Security and uncheck both “Tell me if the site I'm visiting is a suspected attack site” and “Tell me if the site I'm visiting is a suspected forgery”), since this device makes a cookie that constantly relays a unique ID for your browser numerous times per hour (*http://ha.ckers.org/blog/20090824/google-safe-browsing-and-chrome-privacy-leak/). If nothing else, the time periods you were on Tor could be linked to your non-Tor firefox usage and thus your IP address that way, since google would be receiving your unique cookie feedback from efferent Tor servers. Anyways, if you use the Tor Network Map, you can monitor the outgoing traffic from your computer through the Tor network, and catch these web-buggy things red-handed.

As I always say, being a BL is like getting a free computer security course, so don't be intimidated, enjoy it. Fun for the whole family.