* - broken_rfc2231: (boolean) Attempt to work around non-RFC * 2231-compliant MUAs by generating both a RFC * 2047-like parameter name and also the correct RFC * 2231 parameter * DEFAULT: false * - canonical: (boolean) Use canonical (RFC 822/2045) CRLF EOLs? * DEFAULT: Uses "\n" * - charset: (string) Encodes the headers using this charset. If empty, * encodes using UTF-8. * DEFAULT: No encoding. * - defserver: (string) The default domain to append to mailboxes. * DEFAULT: No default name. * - lang: (string) The language to use when encoding. * DEFAULT: None specified * - nowrap: (integer) Don't wrap the headers. * DEFAULT: Headers are wrapped. *