content-type一覧plain richtext enriched tab-separated-values html sgml vnd.latex-z vnd.fmi.flexstor uri-list vnd.abc rfc822-headers vnd.in3d.3dml prs.lines.tag vnd.in3d.spot css xml rtf directory calendar vnd.wap.wml vnd.wap.wmlscript vnd.motorola.reflex vnd.fly vnd.wap.sl vnd.wap.si t140 vnd.ms-mediapackage vnd.IPTC.NewsML vnd.IPTC.NITF vnd.curl vnd.DMClientScript parityfec RFC2646／RFC2046 RFC2045／RFC2046 RFC189
メールヘッダの一覧
