# Debug Kit - Mailer Previews

**URL:** <https://discourse.cakephp.org/t/debug-kit-mailer-previews/2011>\
**Category:** Need Help\
**Created:** [February 7, 2017, 9:24pm UTC](https://discourse.cakephp.org/t/debug-kit-mailer-previews/2011 "2017-02-07T21:24:21Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![plenum](https://yyz1.discourse-cdn.com/flex029/user_avatar/discourse.cakephp.org/plenum/32/498_2.png) [@plenum](https://discourse.cakephp.org/u/plenum)\
**Post date:** [February 7, 2017, 9:24pm UTC](https://discourse.cakephp.org/t/debug-kit-mailer-previews/2011/1 "2017-02-07T21:24:21Z")

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I was wondering if in the 3.3.13 Version of CakePHP Version the Function of Mail Preview is already useable without the Plugin which is documented here ([Example Usage — CakePHP Mail Preview](http://cakephp-mail-preview.readthedocs.io/en/latest/usage.html)).

I tried the way described in the Debug Kit but it does not work throwing this exception:

> Mailer class “User” could not be found.