Most computer science units will have a mailing list forum. If you send email to this address, the message will be sent to all people doing the same unit, including the unit instructors. The address for these forums on turing is your unit name with -forum on the end. For example, the COMP131 forum address is comp131-forum@turing.une.edu.au
Note that not all units have a mailing list forum. See your unit notes for information.