Nice, simple and useful!

Thanks very much for this useful plugin! I am using it to block on domain level so that spammers don′t use the “from” mail input to insert our own domain. This makes it easy.

It′s just a plugin to the point without bling bling. Easy to understand and use and it blends perfectly in to the default user interface of CF7 in back end but also in front end for the error message!

The only thing: Would be great if the background color in back end would have the same color like the other tabs of CF7. This dark gray seems bit to dark. But think this is personal reference.

Really nice, thanks a lot for this!