Transactional Email

Optionally, you can configure an SMTP server to send transactional emails. These are used for password resets, project/organization invitations, and notifications when a batch export is completed.

Configuration

To enable transactional emails, set the following environment variables on the application containers:

AWS SES

When SMTP_CONNECTION_URL is set to ses://<region>, Langfuse sends transactional emails through AWS SES using the SESv2 API. No additional configuration variables are required — credentials are resolved through the default AWS credential chain (IAM role, IRSA, ECS task role, SSO, AWS_PROFILE, or environment variables), which mirrors the credential handling used for S3 blob storage.

If Langfuse is running on AWS, we recommend attaching an IAM role to the Langfuse container with permission to send via SES:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": ["ses:SendEmail"],
      "Effect": "Allow",
      "Resource": "*",
      "Sid": "LangfuseSendEmail"
    }
  ]
}

Make sure the EMAIL_FROM_ADDRESS is a verified identity in the same region, and that your account is out of the SES sandbox if you need to send to arbitrary recipients.

Example configuration:

SMTP_CONNECTION_URL=ses://us-east-1
EMAIL_FROM_ADDRESS=no-reply@example.com

FAQ

• Which SMTP service to use? It is recommended to use a reputable SMTP service for transactional emails to ensure delivery and prevent abuse. If you do not have a preferred service from your cloud provider, try Resend or Postmark. Both are easy to set up and have generous free tiers.
• Can I use my private inbox? No, private inboxes (like GMail) are generally not recommended and difficult to configure correctly.