IMAP4 ID extension. - Tim Showalter (RFC, 2000)

Sieve: A Mail Filtering Language. - Tim Showalter (RFC, 2001)

Sieve: An Email Filtering Language. - Philip Guenther; Tim Showalter (RFC, 2008)

Sieve Email Filtering: Vacation Extension. - Tim Showalter; Ned Freed (RFC, 2008)

A Set of Simple Authentication and Security Layer (SASL) Mechanisms for OAuth. - William J. Mills; Tim Showalter; Hannes Tschofenig (RFC, 2015)