%% You should probably cite rfc6857 instead of this I-D.
@techreport{ietf-eai-popimap-downgrade-03,
    number =    {draft-ietf-eai-popimap-downgrade-03},
    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-eai-popimap-downgrade/03/},
    author =    {Kazunori Fujiwara},
    title =     {{Post-delivery Message Downgrading for Internationalized Email Messages}},
    pagetotal = 19,
    year =      ** No value found for 'doc.pub_date.year' **,
    month =     ** No value found for 'doc.pub_date' **,
    day =       ** No value found for 'doc.pub_date.day' **,
    abstract =  {The Email Address Internationalization (UTF8SMTP) extension allows UTF-8 characters in mail header fields. POP and IMAP servers support internationalized email messages. If a POP/IMAP client does not support Email Address Internationalization, POP/IMAP servers cannot send Internationalized Email Headers to the client and cannot remove the message. To avoid the situation, this document describes a conversion mechanism for internationalized Email messages to be traditional message format.},
}