gomail Skill (OpenClaw)

Use the gomail sender CLI to send emails (with optional attachments and templates) from OpenClaw. This skill wraps the prebuilt Linux sender binary from the gomail project and exposes its flags as structured parameters.

Installation

Download the latest prebuilt Linux AMD64 release that contains the sender binary:

# From a directory on your PATH or the skill directory
LATEST_URL=$(curl -sL -o /dev/null -w '%{url_effective}' https://github.com/craftslab/gomail/releases/latest)
VERSION=${LATEST_URL##*/}          # e.g. v2.7.2
VERSION_NO_V=${VERSION#v}         # e.g. 2.7.2

# Note: the release tag includes a leading "v", but the tarball filename does not.
wget "https://github.com/craftslab/gomail/releases/download/${VERSION}/gomail_${VERSION_NO_V}_linux_amd64.tar.gz"
tar -xf "gomail_${VERSION_NO_V}_linux_amd64.tar.gz"

# Ensure the binaries are executable
chmod +x sender parser

• Recommended: Place sender on your PATH (e.g. /usr/local/bin/sender) or keep it in the gomail skill directory and invoke it with ./sender.
• This skill assumes a Linux environment compatible with the gomail Linux AMD64 builds.

Configuration

The sender tool reads mail server and sender configuration from a JSON file passed via --config. This skill includes a starter config template at sender.json (in the gomail skill directory). It includes:

• SMTP server settings (host, port, TLS, auth)
• Authentication credentials
• A sender email address (the actual From address)

For OpenClaw, you can:

• Use the bundled config template in the gomail skill directory, sender.json (recommended).
• Or point --config to any other JSON file you manage.

Important: skill/sender.json is a template. Replace the placeholder values with real SMTP credentials and keep secrets out of source control.

Important: The --header flag only controls the human‑readable display name. The actual From email address is read from the sender field in the config file, as described in the gomail README.

Parameters (CLI)

This skill uses the sender command exactly as documented in the gomail README:

usage: sender --recipients=RECIPIENTS [<flags>]

Argument / Flag	Required	Description
--config / -c	✅	Path to config JSON file, e.g. sender.json. Defines SMTP/server settings and the actual sender address.
--recipients / -p	✅	Recipients list, format: alen@example.com,cc:bob@example.com. Supports cc: prefix for CC recipients.
--attachment / -a	❌	Comma‑separated attachment files, e.g. attach1.txt,attach2.txt. Paths are resolved relative to the working directory.
--body / -b	❌	Body text or path to a body file, e.g. body.txt.
--content_type / -e	❌	Content type: HTML or PLAIN_TEXT (default).
--header / -r	❌	Sender display name, combined with sender from config to form the From header (e.g. "Your Name" <noreply@example.com>).
--title / -t	❌	Subject/title text for the email.
--dry-run / -n	❌	If set, only outputs recipient validation JSON and exits; does not send the email.
--help	❌	Show help.
--version	❌	Show application version.

Basic usage

From inside the gomail skill directory (with a bundled config and body file):

./sender \
  --config="sender.json" \
  --attachment="attach1.txt,attach2.txt" \
  --body="body.txt" \
  --content_type="PLAIN_TEXT" \
  --header="Your Name" \
  --recipients="alen@example.com,bob@example.com,cc:catherine@example.com" \
  --title="TITLE"

When integrated in OpenClaw, construct the command with the appropriate flags based on user input. Use --dry-run during testing or when you only need to validate recipients without sending mail:

sender \
  --config="sender.json" \
  --recipients="test@example.com" \
  --dry-run

When to use

• Send email: When the user asks to send an email, notification, or message (optionally with attachments) via SMTP.
• Validate recipients: When the user wants to validate or preview recipients without sending (use --dry-run).
• gomail specific: When the user mentions gomail, gomail sender, or wants to use the gomail CLI for mail delivery from OpenClaw.