Yep it's a scam, not to mention a poorly executed one (I love how the person sends the email with an earthlink address and signs "management"). UTS will never,
EVER ask you for your password over an email.
Also, make sure you're only entering your MacID+password to
https://adweb.cis.mcmaster.ca , muss.cis.mcmaster.ca or
https://maccess.mcmaster.ca/portal/dt servers. You can check by right-clicking the page and clicking on "View Page Info" for Firefox or "Properties" for IE.