mail-header-encode-parameter
mail-header-encode-parameter is an alias for `rfc2047-encode-parameter' in `mail-parse.el
'.
(mail-header-encode-parameter PARAM VALUE)
Return and PARAM=VALUE string encoded in the RFC2047-like style.
This is a substitution for the `rfc2231-encode-string' function, that
is the standard but many mailers don't support it.