Send email

A composite action that sends an email through any SMTP server. It runs inline in the calling job, so sending a notification adds a single step — no separate run or runner. Both STARTTLS (port 587) and SSL (port 465) are supported. The SMTP password is sensitive. Store it in H2O Secure Store and pass it in as a secret input (secret: true), so the value is redacted from logs.

Action

id: send-email
name: Send Email

inputs:
  smtp_host:
    type: string
    required: true
    description: "SMTP server hostname"
  smtp_port:
    type: string
    default: "587"
    description: "SMTP server port (587 for STARTTLS, 465 for SSL)"
  smtp_user:
    type: string
    required: true
    description: "SMTP authentication username"
  smtp_password:
    type: string
    required: true
    secret: true
    description: "SMTP authentication password"
  from_addr:
    type: string
    required: true
    description: "Sender email address"
  to_addr:
    type: string
    required: true
    description: "Recipient email address (comma-separated for multiple)"
  subject:
    type: string
    required: true
    description: "Email subject line"
  body:
    type: string
    required: true
    description: "Email body text"

steps:
  - name: "Send email via SMTP"
    timeout: "1m"
    env:
      SMTP_HOST: "${{ .inputs.smtp_host }}"
      SMTP_PORT: "${{ .inputs.smtp_port }}"
      SMTP_USER: "${{ .inputs.smtp_user }}"
      SMTP_PASSWORD: "${{ .inputs.smtp_password }}"
      FROM_ADDR: "${{ .inputs.from_addr }}"
      TO_ADDR: "${{ .inputs.to_addr }}"
      SUBJECT: "${{ .inputs.subject }}"
      BODY: "${{ .inputs.body }}"
    run: |
      python3 -c "
      import os, smtplib
      from email.message import EmailMessage

      msg = EmailMessage()
      msg['From'] = os.environ['FROM_ADDR']
      msg['To'] = os.environ['TO_ADDR']
      msg['Subject'] = os.environ['SUBJECT']
      msg.set_content(os.environ['BODY'])

      port = int(os.environ['SMTP_PORT'])
      if port == 465:
          smtp = smtplib.SMTP_SSL(os.environ['SMTP_HOST'], port)
      else:
          smtp = smtplib.SMTP(os.environ['SMTP_HOST'], port)
          smtp.starttls()

      smtp.login(os.environ['SMTP_USER'], os.environ['SMTP_PASSWORD'])
      smtp.send_message(msg)
      smtp.quit()
      print(f'Email sent to {os.environ[\"TO_ADDR\"]}')
      "

Publish the action to make it callable from workflows.

Use it from your workflow

Reference your stored SMTP password with ${{ .secrets.<name> }} and pass it to the action via with:

id: train-and-email
name: Train and Email

secrets:
  - name: workspaces/<workspace-id>/secrets/smtp-password
    as: smtp_password

jobs:
  train:
    steps:
      - name: Train model
        run: python train.py

      - uses: <workspace-id>:send-email@latest
        with:
          smtp_host: "smtp.gmail.com"
          smtp_port: "587"
          smtp_user: "workflows@example.com"
          smtp_password: "${{ .secrets.smtp_password }}"
          from_addr: "workflows@example.com"
          to_addr: "team@example.com"
          subject: "Workflow completed"
          body: "The training pipeline finished successfully."