isUnread checks whether one Gmail message has the UNREAD system label. Use it when later work should run only for mail that is still unread.
Example
Mark each newly received message as read only if it remains unread when the action runs:Inputs
Every input field also accepts a compatible
Signal; the example passes email.messageId directly.
Output
The action returns aSignal<boolean> indicating whether the message has Gmail’s UNREAD label when the action runs.
Read state is message-level. In a conversation, other messages in the same thread can have a different state.