Try the following if you are logged into your computer (in your PORT office) but get a message that your password has expired when you try to open your email.

press Ctrl+Alt+Delete at the same time, (image A)

your screen will turn blue and give several options

 the option you want is "change password", (image B)
click on change password and then follow the instructions in the window that appears.

You will now need to log off and then log back on to your computer with the new password. Once you have logged off and back on you should be able to get into your email.