The University of California Electronic Communications Policy is the ultimate UC-wide governing policy regarding the appropriate use of university electronic communication resources.
The UC San Diego community must also follow the UCSD Electronic Communications Procedures and Practices (PPM 135-5). Faculty, staff, and students making use of ACMS facilities must abide by the ACMS Acceptable Use Policies.
UC San Diego departments that communicate with students should be aware of Using Electronic Mail for Official Communications with Students (PPM 160-3).
Email sent by the university with the primary purpose of promoting university commercial products or services must comply with the CAN-SPAM act (PDF).
For a summary of the above policies, see Email: Appropriate Use.