#2838 HTML email decode issues

[Jason Naughton]

There's an app that sends me email that squirrelmail has trouble rendering the HTML version. For example when I attempt to render:

--58e5b87c_643c9869_718
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

bla To bla

--58e5b87c_643c9869_718
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

bla To bla<style>=23e= do-signature img =7Bmax-width: 90%=7D</style>

--58e5b87c_643c9869_718--

The HTML marked up version has =22 which should be understood as " and =7B as { and =7D as } yet squirrelmail does not display any content. I'm using the 2017-04-06 svn snapshot with php 5.6.30 under freebsd. Any advice on how to help squirrelmail decode this email?