Set the Content-disposition header value to "attachment", which means that the attachment file must be provided as a link in the message.
mail disposition inline
String
inline
Set the Content-disposition header value to "inline", which means that the attachment must be rendered within the message contents, at the "cid" location. The rendering depends on the mail client.
mail mode ISO2022JP
String
US-ASCII_ISO-2022-JP_UTF8_QP
headerCharset: US-ASCII if possible, Japanese (ISO-2022-JP) & Quoted-printable if possible, otherwise UTF-8 & Quoted-printable
bodyCharset: US-ASCII if possible, Japanese (ISO-2022-JP) & 7-bit if possible, otherwise UTF-8 & Quoted-printable