Flamingo is a message storage plugin originally created for Contact Form 7, which doesn’t store submitted messages.
After activation of the plugin, you’ll find Flamingo on the WordPress admin screen menu. All messages through contact forms are listed there and are searchable. With Flamingo, you are no longer need to worry about losing important messages due to mail server issues or misconfiguration in mail setup.
For more detailed information, please refer to the Contact Form 7