RFC 8438 · PROPOSED STANDARD · 2018
SUN · 14 JUN 2026
IMAP Extension for STATUS=SIZE
Overview
RFC 8438, “IMAP Extension for STATUS=SIZE”, is a Proposed Standard document published in August 2018 by S. Bosch. The canonical text is published by the RFC Editor.
Abstract
This document adds a new capability called "STATUS=SIZE" to the Internet Message Access Protocol (IMAP). It allows retrieving the total storage size of a mailbox with a single STATUS command rather than retrieving and summing the sizes of all individual messages in that mailbox.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
Read this RFC
The canonical text of RFC 8438 is hosted at rfc-editor.org. Available in TXT,HTML.
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