th23

Provide your users and visitors a simple and straight forward contact form.
The modern design is very clear, easy to navigate and with light-weight JS and CSS code. One big benefit is its flexible positioning in pages and posts as a modern style block or classic shortcode.
To keep your website safe, it comes with built in spam and bot protection, by using Akisment and reCaptcha for messages sent by visitors. The plugin is continuously improved and used on live websites since 2012.
th23 Contact is built with some few goals in mind:
<ul>
<li>Simple and straight forward option for user to contact you</li>
<li>Light-weight code basis without overheads and frameworks</li>
<li>Easy to adapt styling to fit any page design and layout</li>
<li>Fight spam and bots without unnecessary hurdles (admittedly it’s a compromise)</li>
</ul>
See it in action on my <a href="https://thorstenhartmann.de/kontakt/" rel="nofollow ugc">Contact page</a>.
<h4>Usage</h4>
Simply insert a new <code>th23 Contact form</code> block into the post / page using the plus sign in the Gutenberg editor or start typing <code>/th23 Contact form</code>.
Alternatively use the <code>[th23-contact]</code> shortcode directly in the source code editor view of a post / page or insert it as a legacy shortcode block.
<h4>NOTE</h4>
The th23 Contact form block and / or shortcode can only be used once per post / page!
Any second instance in the same post / page will be ignored upon frontend rendering and not show up.
<h4>TIP</h4>
Ensure th23 contact form is enabled for the sepcific post / page – see admin area under <code>Settings</code> -> <code>th23 Contact</code>.

th23 Contact

Simple contact form via block or legacy shortcode with optional spam protection via Akismet and reCaptcha

Dreb Bitanghol

This field will provide you more options and flexibility on how you would like to present an instruction or message to your client’s (or site in general) admin interface.
Features:
<ul>
<li>Support PHP.</li>
<li>Option to hide label when field is displayed.</li>
</ul>
Compatible with Advanced Custom Fields:
<ul>
<li>4 (tested up to 4.4.6)</li>
<li>5 (PRO, tested up to 5.3.7)</li>
</ul>
PS: You need <a href="https://wordpress.org/plugins/advanced-custom-fields/" rel="ugc">Advanced Custom Fields</a> installed to use this.
PPS: Even more awesome if you have <a href="http://www.advancedcustomfields.com/pro/" rel="nofollow ugc">Advanced Custom Fields PRO</a> installed.
Important note: Use this with utmost care.

ACF Enhanced Message Field

Exactly what I needed

Exactly what I needed. You could improve the plugin by making the textarea field look more like an IDE, with system fonts, syntax highlights and so on.

Perfect

Awesome!!

Adds an enhanced version of the default Message field to accept PHP and certainly no wpauto().

th23 Contact vs ACF Enhanced Message Field