Jeffrey

Contact Form 7 is an awesome WordPress plugin that provides all sorts of great features for creating Contact Forms. 
I’ve used it on a lot of sites with great succes.
One thing it doesn’t handle though, are customfields. 
With this plug in you can now use customfields in the mail section of Contact Form 7!
I created this plug-in because I had the need to use the same contact form on numerous places but the email adresses needed to be diffrent for all of them. 
(I was using it to create a showcase website in wich visitors are able to contact the creator of the work/art, without showing the full email adress)
What you could do with this might include:
<ul>
<li>Use the same contact form in different posts/pages</li>
<li>Send custom field values in the email </li>
</ul>
There are many more case-specific examples. I searched for a solution, but there was none to be found. 
This plugin provides an elegant solution that leaves the Contact Form 7 Plugin intact.
<h4>WHAT DOES IT DO?</h4>
This plugin provides a new special mail tag for the mail section of the Contact Form 7 Plugin. It allows you to get custom field values in the mail section of Contact Form 7
<h4>HOW TO USE IT</h4>
After installing and activating the plugin, you should use it like the following:
Double underscores are key!
The plug in recognizes a new special mail tag: 
[_customfield]
The tag alone doesn’t work though! 
You need to add two underscores after the tag: 
[_customfield__]
After this you can enter your custom field key i.e.: 
[_customfield__fieldName]
<h4>NOTE</h4>
Multiple values per key (an array) are converted to a comma separated string.

Contact Form 7 Customfield in mail

This plugin provides a new tag type for the Contact Form 7 Plugin. It allows the use of customfields from a post to be used in the mail section

Tessa (they/them), AuRise Creative

sevenspark

Contact Form 7 – Dynamic Text Extension

With this great plugin, we were able to easily fulfil a customer's request for an extension. 
Thanks a lot

Great Plugin

Extends Contact Form 7 by adding dynamic form fields that accepts shortcodes to prepopulate form fields with default values and dynamic placeholders.

Contact Form 7 Customfield in mail vs Contact Form 7 – Dynamic Text Extension