IMAP4rev2
Your email client (Outlook, Gmail app, Thunderbird, Apple Mail) uses IMAP or JMAP to read mail. Essential for mail server configuration and client integration.
What It Defines
Internet Message Access Protocol v4rev2. Server-side mail access: folder management (mailboxes), message search/fetch/flag operations, IDLE for push notification. The standard for modern email clients.
Canonical (Normative)
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
Every email your company sends or receives goes through SMTP. You need this to configure mail servers, debug delivery failures, and understand SPF/DKIM/DMARC.
The structure of every email header you've ever seen is defined here. Essential for email deliverability debugging and understanding DKIM header signing.