The plugin comes with a few example notifications, but due to the vast number of different scenarios it was impossible to include them all by default.
We recommend creating notifications catered to your specific needs by using one of the examples as a template.
You should first check if your notifications are active and properly set. For more information, please follow the next topic: How to send Notifications?
In some cases the SMTP mail server refuses to send some emails based on destination or email content. Check if your SMTP mail server has no additional filters or restrictions, such as special links inside or long words.