zendframework/zf2 — pull request #6016 by sh3bang (2014-03-21 08:56:58+00:00)
Title: less "quoted-printable" overhead

@Zend/Mail: now no transcoding to ASCII throught "quoted-printable" if header value is already US-ASCII.
Header would be re re-encoded to "quoted-printable" if encoding property of message object has been set to "UTF-8"