Maildir
e-mail format
The Maildir e-mail format is a common way of storing email messages on a file system, rather than in a database. Each message is assigned a file with a unique name, and each mail folder is a file system directory containing these files. Maildir was designed by Daniel J. Bernstein circa 1995, with a major goal of eliminating the need for program code to handle file locking and unlocking through use of the local filesystem. Maildir design reflects the fact that the only operations valid for an email message is that it be created, deleted or have its status changed in some way.
Specifications
A Maildir directory (often named Maildir) usually has three subdirectories named tmp, new, and cur.
The tmp subdirectory temporarily stores e-mail messages that are in the process of being delivered. This subdirectory may also store other kinds of temporary files.
The new subdirectory stores messages that have been delivered, but have not yet been seen by any mail application.
The cur subdirectory stores messages that have already been seen by mail applications.
Maildir++
Sam Varshavchik, the author of the Courier Mail Server and other software, defined the Maildir++ extension to the Maildir format to support subfolders and mail quotas.
The public source identifies “Maildir” as e-mail format. This brief keeps that definition visible, then builds a research path around Maildir, e-mail and format.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Maildir”, the useful work is to connect “e-mail format” to the records capable of establishing context and consequence.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 31, 2026. The linked authority identifier is Q1246497. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1995.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Maildir”, its source revision and the description used here.
- Expand the search: follow Maildir primary sources, Maildir archive and Maildir research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Maildir”?
- Which institution is responsible for the underlying evidence?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “Maildir” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.