RFC 1734: POP3 Authentication Command
Defines the AUTH command for POP3, enabling SASL-based authentication methods beyond USER/PASS.
email security
RFC 7489: DMARC: Domain-based Message Authentication, Reporting, and Conformance
Ties SPF and DKIM together into a single policy record that instructs receivers how to handle failing messages.
RFC 2595: Using TLS with IMAP, POP3 and ACAP
Early TLS-for-email RFC. Obsoleted by RFC 8314 which mandates implicit TLS over the legacy STARTTLS approach.
RFC 8314: Cleartext Considered Obsolete: Use of TLS for Email Submission and Access
Mandates TLS for SMTP submission (port 465/587), IMAP, and POP3. Declares cleartext email protocols obsolete.
RFC 7208: Sender Policy Framework (SPF)
Defines which IP addresses are authorised to send mail for a domain via DNS TXT records.
RFC 4408: Sender Policy Framework (SPF)
Original SPF specification. Obsoleted by RFC 7208 in 2014 with stricter language and clarifications.
RFC 6376: DomainKeys Identified Mail (DKIM) Signatures
Cryptographic signature standard that lets receiving MTAs verify a message was authorised by the sending domain.
RFC 4871: DomainKeys Identified Mail (DKIM) Signatures
Original DKIM specification. Obsoleted by RFC 6376 in 2011.
RFC 3207: SMTP Service Extension for Secure SMTP over TLS (STARTTLS)
Defines the STARTTLS SMTP extension that upgrades a plain-text SMTP connection to TLS in-band.
RFC 4954: SMTP Service Extension for Authentication
Defines the SMTP AUTH command and the SASL framework used to authenticate SMTP clients to submission servers.
