There have been a number of "phishing" scams going around. They usually claim to be from IT at UC Davis. They ask for your username and password. They are not legitimate. Here is what the campus says:
"UC Davis will never ask you to confirm or verify your computing account by providing your password via telephone or email. Requests that ask you to reply to an email or visit a non-campus affiliated Web site to confirm or verify your account by providing your password are called phishing scams. DO NOT RESPOND TO THESE REQUESTS even if they appear to come from an email address ending with "ucdavis.edu"."