%% You should probably cite rfc2076 instead of this I-D.
@techreport{ietf-mailext-mail-attributes-06,
    number =    {draft-ietf-mailext-mail-attributes-06},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-mailext-mail-attributes/06/},
    author =    {Jacob Palme},
    title =     {{Common Internet Message Headers}},
    pagetotal = 27,
    year =      1996,
    month =     oct,
    day =       16,
    abstract =  {This memo contains a table of commonly occurring headers in headings of e-mail messages. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.},
}