G Suite, or Google Apps Domain, is the catchall term for an enterprise version of the Google Services. As a not-for-profit, the EUS is afforded G Suite for free. We can use gmail, google drive, and all the other services offered by Google, but attached to our @mcgilleus.ca email addresses. There once was a dark age pre-2015 where all of EUS operations were run on an open source email client and network mapped hard drive; no longer.
There are tons of Tips & Tricks to getting familiar with G Suite that may be different from your personal email address. Inheriting an email address from your predecessor can be very messy, very clean, or somewhere in between.