Using quoted-printable-encoding the hex-numbers must be written in uppercase letters!
Works: =?iso-8859-1?q?=3F=3F=3F?=
Fails: =?iso-8859-1?q?=3f=3f=3f?=
Using quoted-printable-encoding the hex-numbers must be written in uppercase letters!
Works: =?iso-8859-1?q?=3F=3F=3F?=
Fails: =?iso-8859-1?q?=3f=3f=3f?=