Which Slack feature allows employees to notify all active members of a channel?

The feature that enables employees to notify all active members of a channel is commonly recognized as @channel. This feature sends a notification to everyone currently active in the channel, ensuring they are alerted to important messages or updates. Using @channel is particularly beneficial in collaborative environments where immediate attention is necessary, as it reaches all members who are present, rather than those who may be offline or away.

In contrast, @here only notifies those who are currently active in the channel at that moment, which is more specific than the broader reach of @channel. @everyone can serve a similar purpose to @channel but is generally used in a more restrictive context, such as in direct messages to all members of a workspace. Private messages, on the other hand, do not reach multiple channel members and are intended for direct, one-on-one communication.

Thus, @channel is the most effective feature for notifying all active participants in a channel, making it the correct answer in this scenario.