Users can go to their settings page (from where they send message) and check if they want or do not want to receive email notification for message and announcements.
This permission should asked for logged in users only. Script which is responsible for this permission is loaded only for logged in users.
Can you please recheck if you get that pop-up if not logged in? Disable all cache before testing.
1. User can send to how many users same message at a time?
2. Can you please give me screenshot of “Recipient” and “Security” tab of the settings page of this plugin?
3. Give me a screenshot of the page from where user send a message.
Thank you for your suggestion. Currently if you want to change this setup then you will need to add code in functions.php
May be in future version i will add a settings for this.
If you want to show new announcements to a certain role of users, then select that role only when create announcement.
If you want to show only a specific user, then send them a message.