==================
notmuch-properties
==================

SYNOPSIS
========

**notmuch** **count** **property:**\ <*key*>=<*value*>

**notmuch** **search** **property:**\ <*key*>=<*value*>

**notmuch** **show** **property:**\ <*key*>=<*value*>

**notmuch** **reindex** **property:**\ <*key*>=<*value*>

**notmuch** **tag** +<*tag*> **property:**\ <*key*>=<*value*>


**notmuch** **dump** **--include=properties**

**notmuch** **restore** **--include=properties**

DESCRIPTION
===========

Several notmuch commands can search for, modify, add or remove
properties associated with specific messages.  Properties are
key/value pairs, and a message can have more than one key/value pair
for the same key.

While users can select based on a specific property in their search
terms with the prefix **property:**, the notmuch command-line
interface does not provide mechanisms for modifying properties
directly to the user.

Instead, message properties are expected to be set and used
programmatically, according to logic in notmuch itself, or in
extensions to it.

Extensions to notmuch which make use of properties are encouraged to
report the specific properties used to the upstream notmuch project,
as a way of avoiding collisions in the property namespace.

CONVENTIONS
===========

Any property with a key that starts with "index." will be removed (and
possibly re-set) upon reindexing (see **notmuch-reindex(1)**).

MESSAGE PROPERTIES
==================

The following properties are set by notmuch internally in the course
of its normal activity.

**index.decryption**
    If a message contains encrypted content, and notmuch tries to
    decrypt that content during indexing, it will add the property
    ``index.decryption=success`` when the cleartext was successfully
    indexed.  If notmuch attempts to decrypt any part of a message
    during indexing and that decryption attempt fails, it will add the
    property ``index.decryption=failure`` to the message.

    Note that it's possible for a single message to have both
    ``index.decryption=success`` and ``index.decryption=failure``.
    Consider an encrypted e-mail message that contains another
    encrypted e-mail message as an attachment -- if the outer message
    can be decrypted, but the attached part cannot, then both
    properties will be set on the message as a whole.

    If notmuch never tried to decrypt an encrypted message during
    indexing (which is the default, see ``index.decrypt`` in
    **notmuch-config(1)**), then this property will not be set on that
    message.

**session-key**

    When **notmuch-show(1)** or **nomtuch-reply** encounters a message
    with an encrypted part, if notmuch finds a ``session-key``
    property associated with the message, it will try that stashed
    session key for decryption.

    If you do not want to use any stashed session keys that might be
    present, you should pass those programs ``--decrypt=false``.

    Using a stashed session key with "notmuch show" will speed up
    rendering of long encrypted threads.  It also allows the user to
    destroy the secret part of any expired encryption-capable subkey
    while still being able to read any retained messages for which
    they have stashed the session key.  This enables truly deletable
    e-mail, since (once the session key and asymmetric subkey are both
    destroyed) there are no keys left that can be used to decrypt any
    copy of the original message previously stored by an adversary.

    However, access to the stashed session key for an encrypted message
    permits full byte-for-byte reconstruction of the cleartext
    message.  This includes attachments, cryptographic signatures, and
    other material that cannot be reconstructed from the index alone.

    See ``index.decrypt`` in **notmuch-config(1)** for more
    details about how to set notmuch's policy on when to store session
    keys.

    The session key should be in the ASCII text form produced by
    GnuPG.  For OpenPGP, that consists of a decimal representation of
    the hash algorithm used (identified by number from RFC 4880,
    e.g. 9 means AES-256) followed by a colon, followed by a
    hexadecimal representation of the algorithm-specific key.  For
    example, an AES-128 key might be stashed in a notmuch property as:
    ``session-key=7:14B16AF65536C28AF209828DFE34C9E0``.

**index.repaired**

    Some messages arrive in forms that are confusing to view; they can
    be mangled by mail transport agents, or the sending mail user
    agent may structure them in a way that is confusing.  If notmuch
    knows how to both detect and repair such a problematic message, it
    will do so during indexing.

    If it applies a message repair during indexing, it will use the
    ``index.repaired`` property to note the type of repair(s) it
    performed.

    ``index.repaired=skip-protected-headers-legacy-display`` indicates
    that when indexing the cleartext of an encrypted message, notmuch
    skipped over a "legacy-display" text/rfc822-headers part that it
    found in that message, since it was able to index the built-in
    protected headers directly.

    ``index.repaired=mixedup`` indicates the repair of a "Mixed Up"
    encrypted PGP/MIME message, a mangling typically produced by
    Microsoft's Exchange MTA.  See
    https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling
    for more information.

SEE ALSO
========

**notmuch(1)**,
**notmuch-config(1)**,
**notmuch-dump(1)**,
**notmuch-insert(1)**,
**notmuch-new(1)**,
**notmuch-reindex(1)**,
**notmuch-reply(1)**,
**notmuch-restore(1)**,
**notmuch-show(1)**,
***notmuch-search-terms(7)**
