There is a way to get the attention of a group in Teams without tagging each individual. While this can only be done within the group chat window itself, it saves you from trying to remember each person’s name and tagging them correctly.
To do this, open up a Teams Chat window and type, “@“, followed by the Group Name or Email Address List. Select the group or email and send the message. All users will then receive your message in the Teams Group as well as a notification in their email inbox.