There are many, many reasons not to use your work email address, or work's net service, for anything remotely personal. Here's one more: a California appellate court has ruled that even attorney-client confidentiality doesn't apply when the email is on company servers.
In a 3-0 decision, the Sacramento-based court ruled that a woman sending an email to her attorney, in a matter regarding plans to sue your employer, from your office was akin to "consulting her lawyer in her employer's conference room, in a loud voice, with the door open, so that any reasonable person would expect that their discussion of her complaints about her employer would be overheard". (Google Docs PDF link to decision). Consider yourself warned (though the legal options that apply in Australia are, of course, very different, the principle is still a sound one to follow).
Work E-Mail Not Protected by Attorney-Client Privilege, Court Says [Threat Level | Wired.com]