I used this plugin on many wordpress sites and thought its the best contact form plugin. So I already donated to the developer.
Today I installed the plugin Plugin Inspector and let it scan my installed plugins. I was surprised that it found low and high risk security issues in contact form 7.
I hope Takayuki Miyoshi, that you could find time to read this post and be interested about the details. For security reasons I don't write the risk alerts in this post but send it in a private mail if you allow me to do so.
Thank you :-)