Share Automatically
Share your name and photo with only your contacts or have Messages prompt you before your name and photo are shared in a new conversation (only available after you set up name and photo sharing).
Keep messages
Choose how long to keep message conversations in your account. For example, if you choose 30 Days, your conversations (and all attachments) are available in Messages for 30 days. After that period, they’re automatically removed.
See Manage notifications.
Notify me when my name is mentioned
Receive a notification whenever anyone mentions you in a conversation.
Auto-play message effects
Play full-screen effects automatically when received. See Change Shared with You settings in Messages on Mac