Send Email

Send Email

Use scripts/send_email.sh, resolved relative to this SKILL.md. It supports two explicit transports and never retries through a different transport automatically.

Safety

1. Send only when the user explicitly authorizes delivery and supplies or confirms the recipient.
2. Review the recipient, subject, body, and transport before execution. Never include credentials, private keys, or unrelated local data.
3. Send exactly once. Investigate an uncertain result before retrying.
4. Prefer a macOS Keychain item for SMTP passwords. Never place passwords in files, command arguments, commits, or user-facing output.
5. Use plain-text content. Attachments and HTML are outside this skill's scope.

Select a Transport

• local (default): use /usr/bin/mail and direct Postfix delivery. Choose only when the current network's sender IP is acceptable to the recipient domain.
• smtp: log in to a configured SMTP service over SSL or STARTTLS. Choose when direct delivery is blocked or authenticated sender identity is required. Read [references/smtp.md](references/smtp.md) before use.

Do not fall back from local to smtp automatically: a local result may be delayed or ambiguous, and fallback could send a duplicate.

Send

Pipe a generated body through standard input:

printf '%s\n' 'Report body' | \
  /scripts/send_email.sh \
  --transport local \
  --to 'person@example.com' \
  --subject 'Report subject'

For authenticated SMTP, configure the variables in [references/smtp.md](references/smtp.md), then change the transport:

printf '%s\n' 'Report body' | \
  /scripts/send_email.sh \
  --transport smtp \
  --to 'person@example.com' \
  --subject 'Report subject'

Alternatively pass --body-file '/absolute/path/report.txt'. Use --dry-run to validate inputs and configuration without sending or connecting to the SMTP server.

Interpret Results

• SUBJECT_HEADER_READY reports ASCII or RFC 2047 subject preparation.
• LOCAL_MAIL_ACCEPTED means /usr/bin/mail accepted a local-transport message.
• SMTP_CONFIG_READY and SMTP_AUTHENTICATED describe authenticated SMTP setup and login.
• REMOTE_SMTP_ACCEPTED means the receiving SMTP server accepted the message; require it plus exit code 0 before reporting success.
• REMOTE_SMTP_REJECTED, REMOTE_DELIVERY_DEFERRED, REMOTE_DELIVERY_UNCONFIRMED, SMTP_AUTH_FAILED, and SMTP_SEND_FAILED are failures.
• Say the receiving SMTP server accepted the message; do not claim the recipient read it.
• On nonzero exit, report the exact failure and do not silently switch transports or retry.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: jeffliu05042
• Source: jeffliu05042/send-email-skill
• License: MIT

Install and usage instructions live in the source repository linked above.