[[!img notmuch-logo.png alt="Notmuch logo" class="left"]]
# Frequently Asked Questions

See also [[Less Frequently Asked Questions|lfaq]].

[[!toc levels=2]]

## How come this query matches mails in folder:2013? `notmuch search --output=files folder:inbox`

You have duplicates of a message (or messages) in both folders.

Notmuch searches are message based. Multiple files may be associated
with the same message (i.e. the files have identical Message-ID). A
`folder:` search will match the folder of any of the files. The
`--output=files` option outputs all the files of all matching messages.

## How come my query does not list all the emails on the file system?

You may have emails that have some of the [exclude
tags](https://notmuchmail.org/doc/latest/man1/notmuch-search.html#cmdoption-search-exclude)

Notmuch can be configured to exclude some tags while searching. You
can list excluded tags with

    $ notmuch config get search.exclude_tags
    deleted

To verify this is the reason of the discrepancy, add the excluded tags
explicitly to your query. If the problematic query is

    $ notmuch search --output=files -- folder:inbox

Try

    $ notmuch search --output=files -- folder:inbox tag:deleted

You can also temporarily turn of the excluded tags feature with `--exclude`.

    $ notmuch search --output=files --exclude=false -- folder:inbox

## Shouldn't notmuch support inline PGP?

[Why it might not be a good idea](https://dkg.fifthhorseman.net/notes/inline-pgp-harmful/)

## How do I delete messages

See [[excluding]].

## How do I configure the citation line when replying in Emacs?

        (setq message-citation-line-format "On %a, %d %b %Y, %f wrote:")
        (setq message-citation-line-function 'message-insert-formatted-citation-line)

See help for `message-citation-line-format` for details.

## What are sexp queries?

For the syntax of sexp queries, see [the manual
page](https://notmuchmail.org/doc/latest/man7/notmuch-sexp-queries.html).

To see if your version of notmuch supports them, run

        $ notmuch config get built_with.sexp_queries

## How do I search for messages that have no tags?

To do this directly, you need a recent notmuch compiled with sexp
queries (see above). You can then run

        $ notmuch search --query=sexp --output=messages '(not (tag *))'

The same style of query should work for any prefix, even user defined
prefixes like `List` (see below).

Otherwise, it's possible to accomplish this using two searches in shell. First,
you need to query all tags in the database, and transform the result into a
query that matches messages that have none of those tags:

        $ notmuch search --output=tags \* | sed 's/^/not tag:/;2~1s/^/and /'

Next, use that to query the messages:

        $ notmuch search $(notmuch search --output=tags \* | \
                sed 's/^/not tag:/;2~1s/^/and /')

## How do I search for punctuation, specific special characters, or regexp?

Please see the [notmuch-search-terms manual
page](https://notmuchmail.org/doc/latest/man7/notmuch-search-terms.html) first.

The main thing to understand is that Xapian, and therefore Notmuch, searches are
closer to natural language searches than regular expression
searches. Punctuation is mostly ignored.

The boolean prefix searches (see Boolean and Probabilistic Prefixes in the man
page), such as tag: or path: searches, need an exact match.

For [specific
fields](https://notmuchmail.org/doc/latest/man7/notmuch-search-terms.html#search-prefixes)
it is possible to use regex searches (although these are often
noticeably slower than native Xapian queries). The limited set of
fields is a quirk of implementation which requires a Xapian "value
slot" in the database schema. Adding regex support for more fields to
would require of adding more value slots to the schema. The
performance impact of that needs to be experimentally evaluated, and
assuming it is not too bad, some database upgrade code would need to
be written.

## How do I search for folders or paths with spaces?

The spaces in the names must be escaped. For example if you use bash or zsh,
you can search for messages with tag `foo` in folder `INBOX/folder with spaces`
with this query:

        $ notmuch search tag:foo 'folder:"INBOX/folder with spaces"'

## How do I search for the `List-Id:` header?

See `index.header.<prefix>` in `notmuch-config(1)` for details. TLD;R:

    notmuch config set index.header.List List-Id

## Can I use notmuch with grsec?

Sure! It works out of the box. If you have TPE enabled (trusted path execution),
make sure the user is executing the script belongs to the
`kernel.grsecurity.tpe_gid` (in debian this is grsec-tpe).
This is required in order to run the `pre-new` and `post-new` hooks.

## Can I tag threads?

No. Tagging is message based.

It is possible, however, to make tags propagate to all messages in a thread
using a little bit of scripting in the [post-new
hook](https://notmuchmail.org/doc/latest/man5/notmuch-hooks.html). For example, to add the muted tag to all
messages in threads that have at least one message with the muted tag:

        THREAD_TAGS="muted"
        for tag in "$THREAD_TAGS"; do
                notmuch tag +$tag thread:{tag:$tag}
        done

You can add other tags to `THREAD_TAGS` as needed. Note that this is
one way only; you need to explicitly remove the tag from all the
messages in a thread to stop it from propagating again. See
[notmuch-search-terms](https://notmuchmail.org/doc/latest/man7/notmuch-search-terms.html)
for discussion of `thread:{}` queries.


## How can I extract a git patchset for an email thread?

See
[notmuch-extract-patch](https://github.com/aaptel/notmuch-extract-patch). See
also notmuch-extract-patch in
[mailscripts](https://git.spwhitton.name/mailscripts/).