Mail2Go - Lightweight CLI SMTP client

Mail2Go is a very lightweight command-line SMTP client written in Go, designed to send emails from the command-line easily.

Table of Contents

• Features
• Requirements
• Installation
• Building from Source
• Usage
• Examples
• Contributing
• License

Features

• Send Emails with Ease: Quickly send emails with subject, body, and multiple recipients.
• Attachments Support: Attach multiple files of various types to your emails.
• HTML and Plain Text: Supports both HTML and plain text formats for email bodies.
• Command Line Interface: Easy-to-use CLI arguments for configuring and sending emails.
• Flexible Configuration: SMTP server, TLS, port, username, and password can be configured through CLI arguments or a JSON configuration file.
• Automatic Configuration File Detection: Will automatically search for a default configuration file in the user's config directory if no configuration file is provided (e.g., ~/.config/mail2go/config.json).

Requirements

• Go 1.22 or higher recommended (for build).
• Access to an SMTP server for sending emails.

Installation

1. Download the Linux amd64 binary with wget (more versions on release tab):

   wget https://github.com/KeepSec-Technologies/Mail2Go/releases/download/1.1.6/mail2go_linux_amd64_1.1.6.tar.gz

2. Unpack it with tar

   tar -xf mail2go_linux_amd64_1.1.6.tar.gz

3. Move it to your /usr/local/bin/ (Optional):

   sudo mv mail2go /usr/local/bin/mail2go

Building from Source

1. Ensure you have Go installed on your system. You can download Go from here.

2. Clone the repository:

   git clone https://github.com/KeepSec-Technologies/Mail2Go

3. Navigate to the cloned directory:

   cd Mail2Go

4. Build the tool:

   CGO_ENABLED=0 go build -a -installsuffix cgo -o mail2go .

Usage

Run the Mail2Go tool with the required arguments:

-s, --smtp-server         SMTP server for sending emails
-p, --smtp-port           SMTP server port (Default: 587)
-u, --smtp-username       Username for SMTP authentication
-w, --smtp-password       Password for SMTP authentication
-l, --tls-mode            TLS mode (none, tls-skip, tls)
-f, --from-email          Email address to send from

-c, --config              Path to the SMTP json config file which replaces the above arguments

-t, --to-email            Email addresses that will receive the email, can be multiples (comma-separated)
-h, --subject             Subject of the email
-b, --body                Body of the email
-af, --attachments        File paths for attachments, can be multiples (comma-separated)
-bf, --body-file          File path for email body

Examples

# Basic example:
mail2go -s mail.example.com -p 587 -u user@example.com -w password123 -l tls -f mail2go@example.com -t admin@example.com -h 'Test Mail2Go Subject' -b 'This is a body!' 

# Example with two recipients, the body from an HTML file and two attached files (can be more):
mail2go -s mail.example.com -p 587  -u user@example.com -w password123 -l tls -f mail2go@example.com -t admin@example.com,other@example.com -h 'Test Mail2Go Subject' -bf demo/body.html -af README.md,demo/mail2go-smaller.png

# Example without authentication and no TLS:
mail2go -s mail.example.com -p 25 -l none -f mail2go@example.com -t admin@example.com -h 'Test Mail2Go Subject' -b 'This is a body!' 

# Example of a local SMTP server with a TLS certificate that can't be verified:
mail2go -s localhost -p 587 -u user@example.com -w password123 -l tls-skip -f mail2go@example.com -t admin@example.com -h 'Test Mail2Go Subject' -b 'This is a body!' 

Example of json configuration file to pass to Mail2Go:

{
    "smtp_server": "mail.example.com",
    "smtp_port": 587,
    "smtp_username": "user@example.com",
    "smtp_password": "password_example",
    "tls_mode": "tls",
    "from_email": "mail2go@example.com"
}

Example of the command that goes with it:

mail2go -c demo/config.json -t admin@example.com -h 'Test Mail2Go Subject' -b 'This is a body!' 

If you are using the default configuration file at ~/.config/mail2go/config.json it would look like this:

mail2go -t admin@example.com -h 'Test Mail2Go Subject' -b 'This is a body!' 

Note: CLI arguments will override configuration files (from the --config argument or the default location at ~/.config/mail2go/config.json).

Contributing

Contributions to Mail2Go are welcome. Please fork the repository and submit a pull request with your changes or improvements.

License

This project is licensed under MIT - see the LICENSE file for details.