If I am sending an email via AWS SES with a subject over 45 characters and ending in a question mark (?) then the rest of the email returns code. I have the subject charset set to UTF-8.
Email Subject
abghjkzqlkahjizalalalzcvzpozlkjzmrudiekzprioy? - Breaks email abghjkzqlkahjizalalalzcvzpozlkjzmrudiekzprio? - Works fine abghjkzqlkahjizalalalzcvzpozlkjzmrudiekzprioy! - Works fine
Email Content
=?UTF-8?B?Pw==?=
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_Part_1388091_1156038470.1487563296664"
------=_Part_1388091_1156038470.1487563296664
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.=
w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns:v=3D"urn:schemas-=
microsoft-com:vml"><head><title>asdf</title><meta http-equiv=3D"Content-Typ=
e" content=3D"text/html; charset=3Dutf-8"><meta name=3D"viewport" content=
=3D"width=3Ddevice-width"><style type=3D"text/css">=09=09=09body * {=09=09=
=09=09box-sizing: border-box;=09=09=09=09word-break: break-word;=09=09=09=
=09overflow-wrap: break-word;=09=09=09=09word-wrap: break-word;=09=09=09}=
=09=09=09body {=09=09=09=09padding: 0;=09=09=09=09margin: 0;=09=09=09=09bac=
kground: #FFFFFF;=09=09=09}=09=09=09#page {=09=09=09=09=.....