Comment 2 for bug 1098478

I added a related branch, it has a fix for this bug (although I'm not sure how to request a pull to trunk).

Fixed mail header:
--===============7685674442027015972==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit

two headers
--===============7685674442027015972==
Content-Type: application/x-mobipocket-ebook;
 name="=?utf-8?b?U3VwZXJqYXpkYS4gSmXFumR6acSHIHogcHJ6eWplbW5vxZtjacSFXyBDenkg?=
 =?utf-8?q?jazda_samochodem_jest_niebezpieczna=5F=2Emobi?="
MIME-Version: 1.0
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename="=?utf-8?b?U3VwZXJqYXpkYS4gSmXFumR6acSHIHogcHJ6eWplbW5vxZtjacSFXyBDenkg?=
 =?utf-8?q?jazda_samochodem_jest_niebezpieczna=5F=2Emobi?="