You can search by their name, by typing in their last name in the MATC directory.
When you are in your MATC Google email, start typing their name and you will see a list of names start to pop up. The more you type, the smaller the list gets. Then you can click on their name in the list.
You can usually find their email address in Blackboard by going into your course, and looking for a link on the left such as "Faculty Information" or "Contact Information" or something like that.
The email address is probably also listed on the syllabus for the course.