Turn Off @all Mentions In Webex App
A user may sometimes want to control the number of @all messages sent within a space and which are sent in different parts of the space. The moderator can disable @all so that no one in the space can mention everyone at the same time, if that is something they want to prevent.
You can disable @mentions to all, by going to the Space Information section, and then clicking on Disable @mentions to all.
If you use the Webex App to access Webex from your mobile device you will also be able to turn it off, but you can only do it on the desktop.
Please go to Space Information and click on the Enable @mentions to all button if you wish to enable @mentions to all again.