You can use mentions to alert specific people to something in Podio in a comment or a status post. To @mention someone, start typing @[person's name] into a comment or status post, and a list will auto-search for all the people with that name. Click the name of the person you'd like to mention or press enter to mention them.
If the person is not a member of the specific workspace in which you're mentioning them, you'll be asked if you'd like to invite them. Or, if you mention someone on an app item and they don't already have access, then they will get access to that single item automatically (Read more about item share).
You don't have to mention someone who's already following an item, so if someone has commented on the item before or if they're in any way following the item, they will already be notified that you've added a comment to that item.
It's important to remember that Podio pulls the @ mention user list from your Podio Connections tab.
The Connections tab as it appears in Podio.
What does this mean? You are "connected" to someone when you have or have shared a Workspace with them. So even if you no longer share a Workspace with that user, you will still have them as a Connection. Keep in mind that if an item is shared with an outside user, you might not have a connection to them!
If you no longer wish to remain "connected" with a user, simply go to your Connections tab and remove the connection. However, keep in mind that if you share a Workspace with that user in the future, they will automatically be re-added as a Connection.
Mentioning guest members
If you are unable to mention a specific guest user, check to see if they're in your Podio connections. Guest users are not members of a workspace, so other workspace members won't be able to @mention this guest. Guests are automatically following an item and will still get your comments through notifications.
Mentioning all members of a workspace
You can also mention everyone in a specific workspace. Just start typing @[workspace name] and you will mention everyone who's a member of the workspace. This could be good to alert everyone to something that has happened.