This situation can arise when there are a large number of people using one email system, as is the case at HSU, where staff, students, and faculty all have @humboldt.edu addresses. It's obviously something that needs to be avoided, as email may contain confidential information.
When you start typing a name into the To: field in GMail, the system offers up a list of choices; that choice gets smaller as you enter more letters of your addressee's name. You'll also see that different versions of email addresses appear in <> after the person's "plain text" name. If you see two different variations of the "initials+number" name format after identical plain text names, that's a good indication that there are two people of the same name in the HSU mailing list. Staff and faculty, but not students, are automatically provided with a formal email alias in the format firstname.lastname@example.org, which can often help to distinguish them.
The most reliable way to make sure your mail goes to the correct individual is to check their initials+number in the HSU Staff & Faculty Online Directory. Enter your intended recipient's name in the search box and a list will be displayed of all current staff and faculty members with that name, along with their email address, telephone number, department, location, and title. Use this email address to identify your target recipient in GMail. If a duplicate name doesn't show up here, that means the duplicate name displayed by GMail belongs to a student.