If you're sending a message that requires attention in a timely manner, you can set the priority for the message, allowing the recipient to find it quickly. ... In the “Tags” section of the “Message” tab, click “High Importance”, if the message has high priority. You can also assign a “Low Importance” to a message.

What are high priority emails?

Gmail has a new feature for its smartphone apps where you can change which emails you get notifications for. It's called High Priority Notifications and you can enable them on a per-account basis if you have multiple accounts configured.

What happens when you send an email with high importance?

High Importance status should exist solely for those emails that require both immediate attention and for which there will be negative consequences if they do not receive immediate attention. If your email merely requires that the recipients read and respond, write “RESPONSE REQUIRED” in the subject line.