%% You should probably cite draft-santos-smtpgrey-02 instead of this revision.
@techreport{santos-smtpgrey-01,
    number =    {draft-santos-smtpgrey-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-santos-smtpgrey/01/},
    author =    {Evan Harris and Hector Santos},
    title =     {{SMTP Service Extension for Greylisting Operations}},
    pagetotal = 18,
    year =      ,
    month =     ,
    day =       ,
    abstract =  {GREYLIST is a SMTP extension to formalize the widely supported Greylisting mail filtering method and to help support SMTP rejected transports by following a new formal structured 4yz server temporary rejection response by including a "retry=time-delay" tag string which SMTP clients can use to optimize the rescheduling of the mail delivery attempts. With adoption, network overhead reduction in wasteful mail delivery attempts will be realized.},
}