If you have a request for a group of related mailings or several mailings to a specific population over a period of time, you will need to submit a separate request for each mailing. You should add a message in the Notes field that this is message # out of # messages so the approvers know that it is not a duplicate submission.
IRB research mailings -- see Mass Emails page for IRB information
Note: Student organizations and non-academic departments may send two mass emails to all students each semester.