All full-time faculty are assigned an extension and an e-mail address on campus. Since adjunct faculty members are generally on campus only at the time their classes meet, it is recommended that you encourage your students to communicate with you through the campus mail rather than phoning the college. (There is a special "Notes for instructors" slot in the mailroom). Since department offices are only open for limited times each day, find out from your department chair the department's phone number and office hours and instruct students to call only during those hours to leave truly important messages. If you have the good fortune to be "sharing" an office with a full time faculty member, check with that person about phone messages from students.