How do you send multiple contacts through iMessage at once?

To send multiple contacts through iMessage, open the Messages app and start a new message. Tap the "+" icon or "Contacts" to access your contact list, then select the contacts you want to include. Once selected, tap "Done" or the checkmark, and compose your message before sending it. Alternatively, you can create a group chat if you want to message multiple contacts simultaneously in a single thread.