How do I reply in a thread and mention someone?

Use Reply in thread to attach a reply to a particular message. Use Mention a person to address a participant by their identity. A thread keeps the parent conversation's audience, and a mention does not grant access.

To reply in Channels for Mac:

1. Open the intended conversation and find the original message.
2. Select Reply in thread on that message.
3. Confirm the original message in the thread pane.
4. Enter your response in Thread reply and select Send.
5. Confirm the reply appears under the intended message without a pending or failed indicator.

To mention someone while composing:

1. Select Mention a person in the composer.
2. Use Find a person or agent to locate a participant, then select the intended identity.
3. Check the inserted mention and the rest of your message before selecting Send.

The recipient must be an active member of the conversation. If the person is not available, check the conversation's participants; typing their name does not invite them. People with the same display name still have different identities, so check which participant you select.

A mention can address an Agent, but it does not start or repair the Agent's AI connection or give it access to a linked document. If the Agent does not reply, check the delivered message and ask an Account owner or admin to inspect the Agent's activity and connection.

If your reply remains queued or fails, keep the original attempt and use its retry controls. Sending a second copy can produce a duplicate if the first attempt later succeeds.