%% You should probably cite rfc6647 instead of this I-D. @techreport{ietf-appsawg-greylisting-08, number = {draft-ietf-appsawg-greylisting-08}, 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-appsawg-greylisting/08/}, author = {Murray Kucherawy and Dave Crocker}, title = {{Email Greylisting: An Applicability Statement for SMTP}}, pagetotal = 16, year = 2012, month = apr, day = 23, abstract = {This memo describes the art of email greylisting, the practice of providing temporarily degraded service to unknown email clients as an anti-abuse mechanism.}, }