Add PHP Mime Mail Parser - https://github.com/php/pecl-mail-mailparse

plugins/php-mime-mail-parser/src/Contracts/Middleware.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace PhpMimeMailParser\Contracts;
+
+use PhpMimeMailParser\MimePart;
+use PhpMimeMailParser\MiddlewareStack;
+
+/**
+ * Process Mime parts by either:
+ *  processing the part or calling the $next MiddlewareStack
+ */
+interface Middleware
+{
+    /**
+     *  Process a mime part, optionally delegating parsing to the $next MiddlewareStack
+     *
+     * @param MimePart $part
+     * @param MiddlewareStack $next
+     *
+     * @return MimePart
+     */
+    public function parse(MimePart $part, MiddlewareStack $next);
+}