%% You should probably cite draft-ietf-sml-trust instead of this I-D.
@techreport{happel-structured-email-trust-04,
    number =    {draft-happel-structured-email-trust-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-happel-structured-email-trust/04/},
    author =    {Hans-Jörg Happel and Arnt Gulbrandsen},
    title =     {{Trust and security considerations for Structured Email}},
    pagetotal = 10,
    year =      2025,
    month =     may,
    day =       13,
    abstract =  {This document discusses trust and security considerations for structured email and provides recommendations for message user agents on how to deal with structured data in email messages.},
}