You need to install and activate both Contact Form 7 and Slack plugins first.
Then upload Slack Contact Form 7 plugin to your blog's wp-content/plugins/ directory and activate.
You will see new event type with text When someone sent message through Contact Form 7 in integration setting. If checked then notification will be delivered after Contact Form 7 sent the message through email.
Requires: 3.6 or higher Compatible up to: 3.8.3 Last Updated: 2014-4-18 Downloads: 59