title: Did the Symfony validation rules change with the update?
body: <p>After updating from Symfony 2.x to Symfony 4.x and checking the operation, there was a change in the validation rule of the email address.<br />
  In Symfony 2.x, non-alphanumeric words like &quot;あ@test.co.jp&quot; were repelled by Symfony validation, but not in Symfony 4.x. Did the rules change with the update?<br />
  Also, is there a way to undo the rules?<br />
  With my own validation rules, I'm afraid that the email address I used to use may get caught in the validation.<br />
  Also, if you remove the &quot;@&quot;, you will get a validation error message &quot;Not a valid email address&quot;, so it is considered that the validation itself is working.</p>
  <p>Validation specification code common to Symfony 2.x and Symfony 4.x</p>
  <pre class="lang-yaml prettyprint-override"><code>        Mail:
              - NotBlank: ~
              - Email: ~
  </code></pre>