If you are simply looking for a simple bulk e-mail solution, you may not need the extra functionality (archives, subscription, etc) that LISTSERV provides. If you need a small, internal group communication list, you can request an Active Directory (AD) group.
Groups in Microsoft 365 let you choose a set of people that you wish to collaborate with and easily set up a collection of resources for those people to share. Microsoft 365 Groups include a shared inbox, calendar, and OneDrive for collaboration
Watch the video about Microsoft 365 Groups
Microsoft Teams is an app to help you collaborate, communicate, and share files in a single area with a select group of people. Teams are more robust than Microsoft 365 Groups.
Download the Teams app to your phone and desktop for instant messaging, calling, video meetings, calendar access, and file sharing in real-time.
You can create new Teams or add Teams to your existing Microsoft 365 groups.
LISTSERV is a system that makes it possible to create, manage, and control electronic mailing lists on the UTK network or on the Internet. A listserv may be used for sending individual announcements or for group discussion among subscribers. Discussion can be archived for later viewing.