Lots of existing topics on this here, a quick search should bring them up.
In short, you have 3 options I can think of off the top of my head (I’d recommend #3):
- Mention all your users by username in the post. Not ideal, looks messy, and may require site setting changes based on the number of users you have.
- Mention
@trust_level_0which will notify users TL0 and above (all users). May require a site setting change to increase max user notified per group mention. - Create a category which all users watch the first post of. You can use (Obsolete) Set category tracking level defaults historically to change the user preference for all users to watch the first post of your new category.