Does Plain send email notifications for unread chat messages?
Yes. If a customer receives a chat message and has not read or replied to it within a set window, Plain emails them automatically. This applies to all threads in the Chat channel, including headless or custom integrations built on the Plain API.
How read status is tracked
Plain tracks when a customer reads your messages in the chat widget. If the customer reads or replies to a message before the delay ends, no email is sent.
Marking a thread as read from a headless integration
This is not possible. Only Plain's chat widget can report read status, so there is no way to mark a message as read from a custom interface. If a customer views a message in your own UI but does not reply, Plain cannot tell it has been seen and will still send the email.
There is no per-thread opt-out for the email. If your headless integration tracks read status itself and you need to suppress the email for messages that have been seen but not replied to, contact Plain support to discuss your use case.