Himalaya CLI 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.

If you want a more up-to-date version than the latest release, check out the releases GitHub workflow and look for the Artifacts section. You should find a pre-built binary matching your OS. These pre-built binaries are built from the master branch.

Such binaries are built with the default cargo features. If you want to enable or disable a feature, please use another installation method.

Himalaya CLI can be installed with cargo:

cargo install himalaya

With only IMAP support:

cargo install himalaya --no-default-features --features imap

You can also use the git repository for a more up-to-date (but less stable) version:

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

Himalaya CLI can be installed on Arch Linux with either the community repository:

pacman -S himalaya

or the user repository:

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

If you use yay, it is even simplier:

yay -S himalaya-git

Himalaya CLI can be installed with Homebrew:

brew install himalaya

Himalaya CLI can be installed with Scoop:

scoop install himalaya

Himalaya CLI can be installed on Fedora Linux/CentOS/RHEL via COPR repo:

dnf copr enable atim/himalaya
dnf install himalaya

Himalaya CLI can be installed with Nix:

nix-env -i himalaya

You can also use the git repository for a more up-to-date (but less stable) version:

nix-env -if https://github.com/pimalaya/himalaya/archive/master.tar.gz

Or, from within the source tree checkout:

nix-env -if .

If you have the Flakes feature enabled:

nix profile install himalaya

Or, from within the source tree checkout:

nix profile install

You can also run Himalaya directly without installing it:

nix run himalaya

Himalaya CLI can be installed from sources.

First you need to install the Rust development environment (see the rust installation documentation):

curl https://sh.rustup.rs -sSf | sh

Then, you need to clone the repository and install dependencies:

git clone https://github.com/pimalaya/himalaya.git
cd himalaya
cargo check

Now, you can build Himalaya:

cargo build --release

Binaries are available under the target/release folder.

When using Proton Bridge, emails are synchronized locally and exposed via a local IMAP/SMTP server. This implies 2 things:

• Id order may be reversed or shuffled, but envelopes will still be sorted by date.
• SSL/TLS needs to be deactivated manually.
• The password to use is the one generated by Proton Bridge, not the one from your Proton Mail account.

[accounts.proton]
email = "example@proton.me"

backend.type = "imap"
backend.host = "127.0.0.1"
backend.port = 1143
backend.encryption.type = "none"
backend.login = "example@proton.me"
backend.auth.type = "password"
backend.auth.raw = "*****"

message.send.backend.type = "smtp"
message.send.backend.host = "127.0.0.1"
message.send.backend.port = 1025
message.send.backend.encryption.type = "none"
message.send.backend.login = "example@proton.me"
message.send.backend.auth.type = "password"
message.send.backend.auth.raw = "*****"

Keeping your password inside the configuration file is good for testing purpose, but it is not safe. You have 2 better alternatives:

• Save your password in any password manager that can be queried via the CLI:

  backend.auth.cmd = "pass show proton"
  

• Use the global keyring of your system (requires the keyring cargo feature):

  backend.auth.keyring = "proton-example"
  

  Running himalaya configure -a proton will ask for your IMAP password, just paste the one generated previously.

Google passwords cannot be used directly. There is two ways to authenticate yourself:

Using App Passwords

This option is the simplest and the fastest. First, be sure that:

• IMAP is enabled
• Two-step authentication is enabled
• Less secure app access is enabled

First create a dedicated password for Himalaya.

[accounts.gmail]
email = "example@gmail.com"

folder.aliases.inbox = "INBOX"
folder.aliases.sent = "[Gmail]/Sent Mail"
folder.aliases.drafts = "[Gmail]/Drafts"
folder.aliases.trash = "[Gmail]/Trash"

backend.type = "imap"
backend.type.host = "imap.gmail.com"
backend.type.port = 993
backend.type.login = "example@gmail.com"
backend.type.auth.type = "password"
backend.type.auth.raw = "*****"

message.send.backend.type = "smtp"
message.send.backend.host = "smtp.gmail.com"
message.send.backend.port = 465
message.send.backend.login = "example@gmail.com"
message.send.backend.auth.type = "password"
message.send.backend.auth.cmd = "*****"

Keeping your password inside the configuration file is good for testing purpose, but it is not safe. You have 2 better alternatives:

• Save your password in any password manager that can be queried via the CLI:

  backend.auth.cmd = "pass show gmail"
  

• Use the global keyring of your system (requires the keyring cargo feature):

  backend.auth.keyring = "gmail-example"
  

  Running himalaya configure -a gmail will ask for your IMAP password, just paste the one generated previously.

Using OAuth 2.0

This option is the most secure but the hardest to configure. It requires the oauth2 and keyring cargo features.

First, you need to get your OAuth 2.0 credentials by following this guide. Once you get your client id and your client secret, you can configure your Himalaya account this way:

[accounts.gmail]
email = "example@gmail.com"

folder.aliases.inbox = "INBOX"
folder.aliases.sent = "[Gmail]/Sent Mail"
folder.aliases.drafts = "[Gmail]/Drafts"
folder.aliases.trash = "[Gmail]/Trash"

backend.type = "imap"
backend.host = "imap.gmail.com"
backend.port = 993
backend.login = "example@gmail.com"
backend.auth.type = "oauth2"
backend.auth.client-id = "*****"
backend.auth.client-secret.keyring = "gmail-oauth2-client-secret"
backend.auth.access-token.keyring = "gmail-oauth2-access-token"
backend.auth.refresh-token.keyring = "gmail-oauth2-refresh-token"
backend.auth.auth-url = "https://accounts.google.com/o/oauth2/v2/auth"
backend.auth.token-url = "https://www.googleapis.com/oauth2/v3/token"
backend.auth.pkce = true
backend.auth.scope = "https://mail.google.com/"

message.send.backend.type = "smtp"
message.send.backend.host = "smtp.gmail.com"
message.send.backend.port = 465
message.send.backend.login = "example@gmail.com"
message.send.backend.auth.type = "oauth2"
message.send.backend.auth.client-id = "*****"
message.send.backend.auth.client-secret.keyring = "gmail-oauth2-client-secret"
message.send.backend.auth.access-token.keyring = "gmail-oauth2-access-token"
message.send.backend.auth.refresh-token.keyring = "gmail-oauth2-refresh-token"
message.send.backend.auth.auth-url = "https://accounts.google.com/o/oauth2/v2/auth"
message.send.backend.auth.token-url = "https://www.googleapis.com/oauth2/v3/token"
message.send.backend.auth.pkce = true
message.send.backend.auth.scope = "https://mail.google.com/"

Running himalaya configure -a gmail will complete your OAuth 2.0 setup and ask for your client secret.

[accounts.outlook]
email = "example@outlook.com"

backend.type = "imap"
backend.host = "outlook.office365.com"
backend.port = 993
backend.login = "example@outlook.com"
backend.auth.type = "password"
backend.auth.raw = "*****"

message.send.backend.type = "smtp"
message.send.backend.host = "smtp-mail.outlook.com"
message.send.backend.port = 587
message.send.backend.encryption.type = "start-tls"
message.send.backend.login = "example@outlook.com"
message.send.backend.auth.type = "password"
message.send.backend.auth.raw = "*****"

Keeping your password inside the configuration file is good for testing purpose, but it is not safe. You have 2 better alternatives:

• Save your password in any password manager that can be queried via the CLI:

  backend.auth.cmd = "pass show outlook"
  

• Use the global keyring of your system (requires the keyring cargo feature):

  backend.auth.keyring = "outlook-example"
  

  Running himalaya configure -a outlook will ask for your IMAP password, just paste the one generated previously.

Using OAuth 2.0

This option is the most secure but the hardest to configure. First, you need to get your OAuth 2.0 credentials by following this guide. Once you get your client id and your client secret, you can configure your Himalaya account this way:

[accounts.outlook]
email = "example@outlook.com"

backend.type = "imap"
backend.host = "outlook.office365.com"
backend.port = 993
backend.login = "example@outlook.com"
backend.auth.type = "oauth2"
backend.auth.client-id = "*****"
backend.auth.client-secret.keyring = "outlook-oauth2-client-secret"
backend.auth.access-token.keyring = "outlook-oauth2-access-token"
backend.auth.refresh-token.keyring = "outlook-oauth2-refresh-token"
backend.auth.auth-url = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize"
backend.auth.token-url = "https://login.microsoftonline.com/common/oauth2/v2.0/token"
backend.auth.pkce = true
backend.auth.scopes = ["https://outlook.office.com/IMAP.AccessAsUser.All", "https://outlook.office.com/SMTP.Send"]

message.send.backend.type = "smtp"
message.send.backend.host = "smtp.mail.outlook.com"
message.send.backend.port = 587
message.send.backend.starttls = true
message.send.backend.login = "example@outlook.com"
message.send.backend.auth.type = "oauth2"
message.send.backend.auth.client-id = "*****"
message.send.backend.auth.client-secret.keyring = "outlook-oauth2-client-secret"
message.send.backend.auth.access-token.keyring = "outlook-oauth2-access-token"
message.send.backend.auth.refresh-token.keyring = "outlook-oauth2-refresh-token"
message.send.backend.auth.auth-url = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize"
message.send.backend.auth.token-url = "https://login.microsoftonline.com/common/oauth2/v2.0/token"
message.send.backend.auth.pkce = true
message.send.backend.auth.scopes = ["https://outlook.office.com/IMAP.AccessAsUser.All", "https://outlook.office.com/SMTP.Send"]

Running himalaya configure -a outlook will complete your OAuth 2.0 setup and ask for your client secret.

From the iCloud Mail support page:

• IMAP port = 993.
• IMAP login = name of your iCloud Mail email address (for example, johnappleseed, not johnappleseed@icloud.com)
• SMTP port = 587 with STARTTLS
• SMTP login = full iCloud Mail email address (for example, johnappleseed@icloud.com, not johnappleseed)

[accounts.icloud]
email = "johnappleseed@icloud.com"

backend.type = "imap"
backend.host = "imap.mail.me.com"
backend.port = 993
backend.login = "johnappleseed"
backend.auth.type = "password"
backend.auth.raw = "*****"

message.send.backend.type = "smtp"
message.send.backend.host = "smtp.mail.me.com"
message.send.backend.port = 587
message.send.backend.encryption.type = "start-tls"
message.send.backend.login = "johnappleseed@icloud.com"
message.send.backend.auth.type = "password"
message.send.backend.auth.raw = "*****"

Keeping your password inside the configuration file is good for testing purpose, but it is not safe. You have 2 better alternatives:

• Save your password in any password manager that can be queried via the CLI:

  backend.auth.cmd = "pass show icloud"
  

• Use the global keyring of your system (requires the keyring cargo feature):

  backend.auth.keyring = "icloud-example"
  

  Running himalaya configure -a icloud will ask for your IMAP password, just paste the one generated previously.

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

Additionaly, Himalaya CLI is based on email-lib, which is also part of the Pimalaya project. The aim is not just to propose a new terminal interface, but also to expose Rust tools to deal with emails. Anyone who knows Rust language can build his own email interface, without re-inventing the wheel.

An email message is a list of headers (key: val) followed by a body. They form together a template:

Header: value
Header: value
Header: value

Body

Headers and body must be separated by an empty line.

Headers

Here a non-exhaustive list of valid email message template headers:

• Message-ID: represents the message identifier (you usually do not need to set up it manually)
• In-Reply-To: represents the identifier of the replied message
• Date: represents the date of the message
• Subject: represents the subject of the message
• From: represents the address of the sender
• To: represents the addresses of the receivers
• Reply-To: represents the address the receiver should reply to instead of the From header
• Cc: represents the addresses of the other receivers (carbon copy)
• Bcc: represents the addresses of the other hidden receivers (blind carbon copy)

An address can be:

• a single email address user@domain
• a named address Name <user@domain>
• a quoted named address "Name" <user@domain>

Multiple address are separated by a coma ,: user@domain, Name <user@domain>, "Name" <user@domain>.

Plain text body

Email message template body can be written in plain text. The result will be compiled into a single text/plain MIME part:

From: alice@localhost
To: Bob <bob@localhost>
Subject: Hello from Himalaya

Hello, world!

MML body

Email message template body can also be written in MML. The MIME Meta Language was introduced by the Emacs mml ELisp module. Pimalaya ported it in Rust.

A raw email message is structured according to the MIME standard. This standard produces verbose, non-friendly messages. Here comes MML: it simplifies the way email message body are structured. Thanks to its simple XML-based syntax, it allows you to easily add multiple parts, attach a binary file, or attach inline image to your body without dealing with the MIME standard.

For instance, this MML template:

From: alice@localhost
To: bob@localhost
Subject: MML simple

<#multipart type=alternative>
This is a plain text part.
<#part type=text/enriched>
<center>This is a centered enriched part</center>
<#/multipart>

compiles into the following MIME Message:

Subject: MML simple
To: bob@localhost
From: alice@localhost
MIME-Version: 1.0
Date: Tue, 29 Nov 2022 13:07:01 +0000
Content-Type: multipart/alternative;
 boundary="4CV1Cnp7mXkDyvb55i77DcNSkKzB8HJzaIT84qZe"

--4CV1Cnp7mXkDyvb55i77DcNSkKzB8HJzaIT84qZe
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

This is a plain text part.
--4CV1Cnp7mXkDyvb55i77DcNSkKzB8HJzaIT84qZe
Content-Type: text/enriched
Content-Transfer-Encoding: 7bit

<center>This is a centered enriched part</center>
--4CV1Cnp7mXkDyvb55i77DcNSkKzB8HJzaIT84qZe--

See more examples at pimalaya/core/mml.

Read first about the FAQ: How to compose a message?.

From: alice@localhost
To: bob@localhost
Subject: How to attach stuff

Regular binary attachment:
<#part filename=/path/to/file.pdf><#/part>

Custom file name:
<#part filename=/path/to/file.pdf name=custom.pdf><#/part>

Inline image:
<#part disposition=inline filename=/path/to/image.png><#/part>

See more examples at pimalaya/core/mml.

The simplest way is to use --debug and --trace arguments.

The advanced way is based on environment variables:

• RUST_LOG=<level>: determines the log level filter, can be one of off, error, warn, info, debug and trace.
• RUST_SPANTRACE=1: enables the spantrace (a span represent periods of time in which a program was executing in a particular context).
• RUST_BACKTRACE=1: enables the error backtrace.
• RUST_BACKTRACE=full: enables the full error backtrace, which include source lines where the error originated from.

Logs are written to the stderr, which means that you can redirect them easily to a file:

RUST_LOG=debug himalaya 2>/tmp/himalaya.log

All the lookup mechanisms use the email address domain as base for the lookup. It is heavily inspired from the Thunderbird Autoconfiguration protocol. For example, for the email address test@example.com, the lookup is performed as (in this order):

1. check for autoconfig.example.com
2. look up of example.com in the ISPDB (the Thunderbird central database)
3. look up MX example.com in DNS, and for mx1.mail.hoster.com, look up hoster.com in the ISPDB
4. look up SRV example.com in DNS
5. try to guess (imap.example.com, smtp.example.com…)