himalaya

Table of contents

• Features
• Installation
• Configuration
• Usage
• Interfaces
• FAQ
• AI policy
• License
• Social
• Contributing
• Sponsoring

Features

• Shared API for mailboxes, envelopes, flags, messages and attachments
• Protocol-specific APIs exposing each backend's full surface
• IMAP, SMTP, ManageSieve, JMAP, Gmail (REST API), Microsoft Graph (Outlook / Microsoft 365) support
• Maildir specs, m2dir specs, mbox specs, pimdir specs support
• Simple auth support for IMAP, SMTP and ManageSieve (anonymous, login, plain, oauthbearer, xoauth2, scram-sha-256)
• HTTP auth support for JMAP: basic, bearer
• TLS support:
  • Rustls with ring crypto
  • Rustls with aws crypto (requires rustls-aws feature)
  • Native TLS (requires native-tls feature)
• Discovery support:
  • PACC specs
  • Autoconfiguration (Thunderbird) specs
  • SRV DNS lookups rfc6186
  • JMAP session resolution rfc8620
• SOCKS5, HTTP proxy support, per account or via $ALL_PROXY and $HTTPS_PROXY
• TOML configuration with multi-account support
• JSON output via --json
• REPL via himalaya repl, running commands over connections kept for the session
• MCP server via himalaya mcp, the shared API as tools, read-only by default

[!TIP] Himalaya is written in Rust and uses cargo features to gate backend support. The default feature set is declared in Cargo.toml.

The default wizard feature brings the interactive configure; leave it out of a scripted or embedded build that never prompts.

The default vendored feature builds SQLite from source; leave it out (--no-default-features --features …) to link the system one.

Installation

Pre-built binary

Himalaya can be installed with the installer:

As root:

curl -sSL https://raw.githubusercontent.com/pimalaya/himalaya/master/install.sh | sudo sh

As a regular user:

curl -sSL https://raw.githubusercontent.com/pimalaya/himalaya/master/install.sh | PREFIX=~/.local sh

These commands install the latest binary from the GitHub releases section.

For a more up-to-date version than the latest release, check out the releases GitHub workflow and look for the Artifacts section. These pre-built binaries are built from the master branch.

[!NOTE] Such binaries are built with the default cargo features. If you need specific features, please use another installation method.

Cargo

cargo install --locked --git https://github.com/pimalaya/himalaya.git

With only IMAP+SMTP support:

cargo install --locked --git https://github.com/pimalaya/himalaya.git \
  --no-default-features \
  --features imap,smtp,rustls-ring

Arch Linux

From the community repository:

pacman -S himalaya

Or the user repository:

git clone https://aur.archlinux.org/himalaya-git.git
cd himalaya-git
makepkg -isc

Or with yay:

yay -S himalaya-git

Homebrew

brew install himalaya

[!NOTE] Cargo features are not compatible with brew. If you need a different feature set, please use another installation method.

Scoop

scoop install himalaya

Fedora Linux/CentOS/RHEL

From the COPR repo:

dnf copr enable atim/himalaya
dnf install himalaya

Nix

If you have the Flakes feature enabled:

nix profile install github:pimalaya/himalaya

Or run without installing:

nix run github:pimalaya/himalaya

Sources

Requires Rust 1.89 or later:

git clone https://github.com/pimalaya/himalaya
cd himalaya
cargo build --release --locked

The binary lands at target/release/himalaya.

Configuration

Run himalaya. With no configuration file on disk, the wizard asks for an email address and discovers the services reachable from it, probing PACC, Thunderbird Autoconfiguration, RFC 6186 SRV and RFC 8620 JMAP resolution in parallel.

Each domain, mail and sending, gets the best option found without a question (a provider's own API first, then JMAP, then IMAP and SMTP), shown in a review where any pick can be changed, a custom server URL included. Then each sign-in runs once: a password is typed once, tested at once, and stored in an installed keyring (or kept raw, or read by your own command); OAuth 2.0 hands off to Ortie when it is installed. When discovery finds nothing, the wizard asks for the server URL (imaps://, imap:// or https://, then smtps:// or smtp:// for sending). The account is then written to disk.

A persistent configuration is loaded from every existing path among the following, each one deep-merged on top of the ones before, so $HOME/.himalayarc overrides the others (a path naming a file already loaded, such as a symlinked rc file, is skipped):

• $XDG_CONFIG_HOME/himalaya/config.toml
• $HOME/.config/himalaya/config.toml
• $HOME/.himalayarc

At most one account may be marked default = true across them: an rc file moving the default sets default = false on the account the other file marks.

These are the same paths the himalaya-tui TUI looks at: one TOML file backs both binaries. CLI-only fields and TUI-only sections coexist without errors. See config.sample.toml for a documented template.

Override those paths with -c <PATH>; multiple paths can be passed at once, separated by ; on Windows and : elsewhere, as $PATH separates them, or by repeating -c. The first one is the base and the rest are deep-merged on top.

To add an account, run himalaya configure: the account is appended to your config file, or printed when stdout is redirected. There is no in-place edit subcommand; himalaya account list and himalaya account check inspect and validate the accounts already declared.

Proton Mail

Proton does not expose IMAP/SMTP directly: run Proton Bridge, which synchronizes mail locally and serves it on a local IMAP/SMTP endpoint. The password is the one generated by the Bridge, not your Proton account password.

[accounts.proton]

imap.server = "imap://127.0.0.1:1143"
imap.sasl.plain.username = "[email protected]"
imap.sasl.plain.password.command = "pass show proton-bridge"

smtp.server = "smtp://127.0.0.1:1025"
smtp.sasl.plain.username = "[email protected]"
smtp.sasl.plain.password.command = "pass show proton-bridge"

To keep TLS on the local link, export the certificate generated by the Bridge and enable STARTTLS:

imap.starttls = true
imap.tls.cert = "/path/to/exported/cert.pem"

smtp.starttls = true
smtp.tls.cert = "/path/to/exported/cert.pem"

Fastmail

Fastmail needs an app password for IMAP/SMTP, or an API token for its native JMAP endpoint.

[accounts.fastmail]

imap.server = "imaps://imap.fastmail.com"
imap.sasl.plain.username = "[email protected]"
imap.sasl.plain.password.command = "pass show fastmail"

smtp.server = "smtps://smtp.fastmail.com"
smtp.sasl.plain.username = "[email protected]"
smtp.sasl.plain.password.command = "pass show fastmail"

To use JMAP instead, replace the imap/smtp blocks with a single jmap one:

jmap.server = "https://api.fastmail.com/jmap/session"
jmap.auth.bearer.token.command = "pass show fastmail"

Gmail

Gmail rejects the account password over SASL PLAIN: generate an app password (requires 2-step verification) and feed it through password.command or password.raw.

[accounts.gmail]

imap.server = "imaps://imap.gmail.com:993"
imap.sasl.plain.username = "[email protected]"
imap.sasl.plain.password.command = "pass show gmail"

smtp.server = "smtps://smtp.gmail.com:465"
smtp.sasl.plain.username = "[email protected]"
smtp.sasl.plain.password.command = "pass show gmail"

mailbox.alias.inbox = "INBOX"
mailbox.alias.sent = "[Gmail]/Sent Mail"
mailbox.alias.drafts = "[Gmail]/Drafts"
mailbox.alias.trash = "[Gmail]/Trash"
mailbox.alias.archive = "[Gmail]/All Mail"

Every Gmail label shows up as a top-level IMAP mailbox, and the special ones live under the [Gmail]/ prefix, so quote them in the shell or reach them through an alias.

[Gmail]/All Mail is the archive holding every message, so aliasing it puts "search everything" one flag away: himalaya envelope search -m archive ....

To use Gmail's native REST API instead of IMAP/SMTP, replace the blocks above with a single OAuth 2.0 bearer token from a helper such as ortie:

gmail.auth.token.command = ["ortie", "token", "show", "-a", "gmail"]

Labels become mailboxes here too, but they carry the API's opaque label ids; address them by name (-m Himalaya-Test) and himalaya resolves the id.

Outlook

Microsoft has retired basic authentication: use OAuth 2.0 via oauthbearer or xoauth2, with the access token supplied by an external helper such as ortie.

[accounts.outlook]

imap.server = "imaps://outlook.office365.com:993"
imap.sasl.xoauth2.username = "[email protected]"
imap.sasl.xoauth2.token.command = ["ortie", "token", "show", "-a", "outlook"]

smtp.server = "smtp://smtp-mail.outlook.com:587"
smtp.starttls = true
smtp.sasl.xoauth2.username = "[email protected]"
smtp.sasl.xoauth2.token.command = ["ortie", "token", "show", "-a", "outlook"]

To use the native Microsoft Graph API instead of IMAP/SMTP, replace the blocks above with a single OAuth 2.0 bearer token (sending goes through Graph too, so no SMTP is needed):

msgraph.auth.token.command = ["ortie", "token", "show", "-a", "msgraph"]

Mail folders carry Graph's opaque folder ids; address them by name (-m Archive) or by a well-known name (-m inbox) and himalaya resolves the id.

Posteo

Standard IMAP and SMTP with your regular account password: no app password required.

[accounts.posteo]

imap.server = "imaps://posteo.de"
imap.sasl.plain.username = "[email protected]"
imap.sasl.plain.password.command = "pass show posteo"

smtp.server = "smtps://posteo.de"
smtp.sasl.plain.username = "[email protected]"
smtp.sasl.plain.password.command = "pass show posteo"

iCloud Mail

Per the iCloud Mail support page, the IMAP login is the name of your address, johnappleseed rather than [email protected], while the SMTP login is the full address.

A dedicated app-specific password is required.

[accounts.icloud]

imap.server = "imaps://imap.mail.me.com:993"
imap.sasl.plain.username = "johnappleseed"
imap.sasl.plain.password.command = "pass show icloud"

smtp.server = "smtp://smtp.mail.me.com:587"
smtp.starttls = true
smtp.sasl.plain.username = "[email protected]"
smtp.sasl.plain.password.command = "pass show icloud"

mailbox.alias.sent = "Sent Messages"

Usage

Every command carries its own --help, the source of truth for its flags and syntax. The snippets below are a taste of the surface.

Shared API

Backend-agnostic commands run on the account's first configured backend, or the one picked with -b/--backend. -m/--mailbox takes a mailbox id, name, alias or role (inbox, sent, drafts, trash...), and defaults to the inbox.

himalaya mailbox list
himalaya envelope list --page 2
himalaya envelope search from alice and after 2026-01-01 order by date desc
himalaya flag add --flag seen 1 2 3 5
himalaya message read 42
himalaya message copy --from INBOX --to Archives 42
himalaya attachment download 42

envelope search uses himalaya's own cross-backend query DSL: date, after, before, from, to, cc, bcc, address (any of the four), subject, body, flag and attachment clauses, joined with and, or and not, grouped with parentheses, then order by. -h lists the clauses and himalaya envelope search --help gives the grammar and how each backend matches text. A clause a backend cannot search is refused with the code search-unsupported rather than dropped (every flag on Microsoft Graph, flag answered and keywords on Gmail, attachment on IMAP).

Protocol-specific APIs

Each backend also exposes its full native API under its own subgroup, always against that backend (-b/--backend is ignored here):

himalaya imap raw 'a1 SEARCH FROM "[email protected]"\r\n'
himalaya jmap mailbox query --role drafts
himalaya gmail messages list -q "from:alice is:unread"
himalaya msgraph mail-folders list
himalaya smtp send -f [email protected] -t [email protected] < message.eml
himalaya sieve list
himalaya sieve check --script-file filters.sieve
himalaya sieve put main --script-file filters.sieve
himalaya sieve activate main
himalaya pimdir search from:[email protected] has:attachment date:2026-01..2026-03

ManageSieve uses the optional sieve account block. RFC 5804 registers one port, 4190, and reaches TLS on it through STARTTLS, so a bare server address takes sieve:// with the upgrade on where the IMAP and SMTP ones take their implicit-TLS scheme.

sieves:// is accepted too, for the deployments listening for a handshake straight away. A password or a bearer token is refused on an unencrypted connection unless sieve.allow-cleartext-auth says otherwise.

capability, list, get, put, check, activate, deactivate, rename, delete and raw are available, and put and check accept a script file, inline text or stdin.

On a pimdir account, pimdir search, pimdir count, pimdir thread and pimdir tag ask the store's search index in the pimdir query language: words, phrases, field:value terms, and, or, not and parentheses, over the account's mail. The store's sync engine builds the index and refreshes it after each run; Himalaya only reads it, so a message shows once it is synced and indexed, and a line under the results says what they could not see (bodies not downloaded, mail older than what the store holds, the index lagging the store). pimdir tag queues one flag change per matched message for the sync engine to apply.

Composing messages

message compose / reply / forward cover simple cases through flags. For rich MIME (MML directives, signing, encryption, an editor-driven flow), chain a composer such as mml into message send / message add, or stage a prepared file as a draft:

himalaya message compose --to [email protected] --subject Hello --body Hi --send
mml compose >(himalaya message send)
himalaya message add -m drafts --flag draft < message.eml

See himalaya message send --help and the mml docs for the composer chaining.

Re-using sessions

Each invocation opens a fresh TCP+TLS+SASL session. To amortize the handshake, there are two options:

• himalaya repl keeps one process alive for one account: each stdin line is a command without the binary name (envelope list, message read 42), run over clients that connect the first time a command needs them and stay connected for the session. Quote arguments as in a shell; quit, exit or EOF ends it. The account, --backend and --json are given once, on the repl command. Piped, every line gets one answer on stdout (one JSON value per line under --json, a failure being the error object), so a program can drive it. Stdin carries the commands, so a command takes its input as an argument or a file path, never from stdin. SMTP still connects per send, a server dropping an idle SMTP connection after a few minutes, and a command that fails drops its client so the next one connects again.
• sirup serves a pre-authenticated IMAP/SMTP session over a Unix socket that imap.server / smtp.server can point at, shared by every process: the choice for many short invocations, or several tools at once. Do not point a himalaya repl at a sirup socket yet: sirup serves one client at a time and keeps the upstream alive only while none is attached.

MCP server

himalaya mcp runs a Model Context Protocol server over stdio for one account, exposing the shared API as tools (mailbox_list, envelope_list, envelope_search, message_read, attachment_list, attachment_download, the composers, and so on). Each tool takes the arguments of its command, spelled as on the command line (mailbox, page-size, message-ids), and answers the same JSON as --json; an argument a tool does not take is refused, never ignored. Clients connect once for the server's lifetime, as in himalaya repl.

Only the tools that read are listed by default. --allow-write adds the ones that change the store (flags, add, copy, move, delete, saving a composed message, marking a read one seen), and --allow-send the ones that send mail. An agent reading mail can be told by a message to send mail, so think twice before giving it both. Tools never read nor write local files: attachment_download always runs as attachment download --stdout, message parse and the file arguments of the composers are left out, and a message given to message_add or message_send is taken as the message itself, even when it spells a path. attachment_download returns the part's bytes as an embedded resource, and the composers take their attachments inline instead, as attach-data: a list of {filename, mimeType, data, text}, data in base64 or text as is. Either way, an attachment over --max-attachment-size <BYTES> (10 MiB by default) is refused with attachment-too-large. Under --allow-send this lets an agent send any data it holds, not only text.

{
  "mcpServers": {
    "himalaya": { "command": "himalaya", "args": ["mcp", "--account", "work"] }
  }
}

Interfaces

Himalaya CLI is one of several front-ends to the Pimalaya libraries:

• pimalaya/himalaya-tui: official TUI (in active development)
• pimalaya/himalaya-vim: Vim plugin
• dantecatalfamo/himalaya-emacs: Emacs plugin
• jns/himalaya: Raycast extension
• openclaw/openclaw: OpenClaw SKILL
• parisni/dfzf: dfzf integration
• kezhenxu94/himalaya-fzf: interactive fzf front-end

FAQ

Aerc, mutt and alpine can be categorized as Terminal User Interfaces (TUI). When the program is executed, your terminal is locked into an event loop and you interact with your emails using keybinds.

Himalaya is a Command-Line Interface (CLI). There is no event loop: you interact with your emails using shell commands, in a stateless way.

A dedicated TUI (himalaya-tui) is in active development on top of the same Pimalaya libraries, and is definitely closer to aerc, mutt and alpine.

Every *.passwd / *.password / *.token field accepts either a raw literal or a shell command that prints the secret on stdout. The raw form is convenient for testing but should not be used in production:

imap.sasl.plain.passwd.raw = "***"
imap.sasl.plain.passwd.command = "pass show example"
imap.sasl.plain.passwd.command = ["pass", "show", "example"]

Native keyring support was removed in v2. Use a third-party keyring CLI (pass, secret-tool, gopass…) as the command.

v2 ships no OAuth flow. Use ortie, or any other token broker, to obtain an access token, then plug it in as a command printing that token on stdout.

For JMAP, point jmap.auth.bearer.token.command at the broker. For IMAP and SMTP, route the bearer through a SASL mechanism taking a command-sourced password.

The wizard probes several discovery mechanisms in parallel on the email address domain, merges their results and ranks them per domain, implicit TLS before STARTTLS, unencrypted servers dropped:

• PACC draft-ietf-mailmaint-pacc-02: well-known JSON, digest-verified against the _ua-auto-config TXT record.
• Thunderbird Autoconfiguration: ISP main / well-known / ISPDB lookups, then the autoconfig of the provider the MX records name, then the mailconf=<URL> TXT redirect.
• RFC 6186 SRV: _imap._tcp, _imaps._tcp, _submission._tcp lookups assembled into a single report.
• RFC 8620 JMAP: the SRV record and the /.well-known/jmap session resource.

A final WWW-Authenticate probe refines the advertised auth schemes. A Google or Microsoft account, detected by its domain or its MX records, puts the Gmail API or Microsoft Graph first, IMAP and SMTP staying one change away. See io-pim-discovery for the full chain.

Use --log-level <level> (alias --log) where <level> is one of off, error, warn, info, debug, trace:

himalaya --log trace mailbox list

The RUST_LOG environment variable is consulted when --log is not passed, and supports per-target filters (see the env_logger documentation). RUST_BACKTRACE=1 enables full error backtraces.

Logs are written to stderr, so they can be redirected easily to a file:

himalaya --log trace mailbox list 2>/tmp/himalaya.log

You can also send logs straight to a file via --log-file <path>:

himalaya --log trace --log-file /tmp/himalaya.log mailbox list

Set NO_COLOR=1 in your environment.

License

This project is licensed under either of:

• MIT license
• Apache License, Version 2.0

Social

• Chat on Matrix
• News on Mastodon or RSS
• Mail at [email protected]

Sponsoring

Special thanks to the NLnet foundation and the European Commission that have been financially supporting the project for years:

• 2022 → 2023: NGI Assure
• 2023 → 2024: NGI Zero Entrust
• 2024 → 2026: NGI Zero Core
• 2026 → 2027: NGI Zero Commons Fund

This program is part of Pimalaya, free software funded entirely by grants and donations. If you find it useful, consider sponsoring its development: