Send an inline reply to a message on Mac
With macOS 11 or later, you can send an inline reply to a specific message in a conversation. Inline replies improve clarity and help keep conversations organized by creating new threads.
Note: To send inline replies, you need to use iMessage for individual messages; for a group conversation, as long as there’s at least one other iMessage user in the group, inline replies can be sent.
Siri: Say something like: “Reply that’s great news.” Learn how to use Siri.
In the Messages app on your Mac, select a conversation.
Control-click the message or attachment, then choose Reply (or use the Touch Bar).
Tip: If you have a trackpad or a Magic Mouse and are using macOS Sonoma or later, you can swipe right with two fingers on the message or attachment.
Enter your message in the field at the bottom of the window, then press Return on your keyboard to send it.