You have multiple options you can use to communicate with a particular Group depending on your account's Admin status as well as if you are part of a group or not.
Posting to a Group - if you are in the group
If you are a member of a group you can put simply post to the wall of the Group in question, everyone will be informed that the post has been created. They can comment on the post, which is a great way to begin a discussion. All admin members are automatically placed by the system into the Ambassadors and Reps Group, so admins can communicate with each other really easily.
Select the group you want to share with by scrolling (on a mobile - see screenshot below) or using the drop down list (on desktop) next to the 'Post to" prompt to find the class or group you need.
Sending an Announcement - if you are not in the group
If you have been assigned an admin status by your Ambassador you can switch sides to the green Admin area where you can send an Announcement to a Group, Class, Year or even the Whole School.
This can be viewed by recipients as an app notification, an email and within Classlist. Announcements allow a longer message of up to 10,000 characters, and can also contain an attachment, images, text formatting etc making them more suitable for longer or newsletter type messages.
Announcements can also be saved as drafts and schedule sent.
Sending an Announcement - reaching parents who haven't joined yet
As well as reaching members of the group you chose, Announcements will be sent to all those who have been invited by email to join by a Classlist Admin (non-members) and also to Family Members added by parents to their profile, regardless of whether or not they have registered yet.
For instance, let's an admin invited 100 parents to join Year 7, and 70 of them registered for Classlist right away. If you now send an announcement to Year 7 it will be sent to be sent to your 70 members via the app and email, and it will also be sent by email to the 30 parents who haven't joined yet. The same will happen with Community Event invitations.
Only admins can send announcements and use community events, and the emails will only be sent to parents invited by an admin at your school. This does not make them a member and they still need to register to join, interact with other parents or appear in the member lists.
However, the above means you can reach all the parents from day 1 of using Classlist.
There is an unsubscribe link if a parent does not wish to receive future announcements or event invitations from you.