I need help for setting up SMTP URL Connection

[Mahesh-ai123]

Describe your question

We are in the process of enabling email notifications (password reset, user invitations, and export notifications) for our Langfuse application hosted in Azure Container Apps. For this feature to work, we are required to configure a valid SMTP connection URL.

I kindly request your support in providing the following details or helping us generate the correct SMTP URL format that is compatible with our organization’s mail server:

SMTP Hostname

Port Number (preferably for STARTTLS or TLS connection)

Authentication requirements

Service account email

App password or SMTP authentication key

Whether STARTTLS/TLS is required

Any organization-specific parameters or restrictions needed in the SMTP URL

Langfuse requires the configuration to be set in this format:

SMTP_CONNECTION_URL=smtp://:@<smtp_host>:?starttls=true

Additionally, please confirm the appropriate FROM email address we can use for transactional emails.

Your assistance will help us complete the setup and ensure smooth email delivery for Langfuse notifications.

Thank you in advance for your support. Please let me know if any further information is required

Langfuse Cloud or Self-Hosted?

Self-Hosted

If Self-Hosted

No response

If Langfuse Cloud

No response

SDK and integration versions

No response

Pre-Submission Checklist

• I have checked for existing issues/discussions and consulted Langfuse AI.

[inkeep-ai-assistant[bot]]

To configure SMTP for transactional emails in Langfuse, you need to set two environment variables on your application containers(1):

• SMTP_CONNECTION_URL - Configure optional SMTP server connection for transactional email(1)
• EMAIL_FROM_ADDRESS - Configure from address for transactional email (required if SMTP_CONNECTION_URL is set)(1)

SMTP Connection URL Format

The connection URL is passed to Nodemailer(1). The format follows Nodemailer's connection string specification, using 'smtp:' or 'smtps:' as the protocol(2).

For STARTTLS connections, the format is:

smtp://<username>:<password>@<smtp_host>:<port>?starttls=true

(2)

Working Examples from the Community

AWS SES example:

SMTP_CONNECTION_URL="smtps://AKIAexampleAWSSMTPUsername:1234ExamplePassword@email-smtp.ap-northeast-1.amazonaws.com:465"
EMAIL_FROM_ADDRESS="dev@company.co.jp"

(3)

Port 25 with STARTTLS:

smtp://smartmail.company.net:25?starttls=true

(2)

Important Configuration Notes

1. The SMTP connection URL should NOT be URL-encoded(4)
2. For Docker Compose deployments, you must pass both SMTP_CONNECTION_URL and EMAIL_FROM_ADDRESS to the langfuse-web image in your docker-compose.yml file(3)
3. It's recommended to use a reputable SMTP service for transactional emails to ensure delivery and prevent abuse(1)

What You Need from Your Organization

To create your SMTP connection URL, you'll need from your IT team:

• SMTP hostname
• Port number (commonly 25 for STARTTLS, 465 for SSL/TLS, or 587 for STARTTLS)
• Service account username/email
• Service account password or app password
• Whether STARTTLS is required (add ?starttls=true parameter if yes)
• The approved FROM email address for transactional emails

Once you have these details, construct your connection string following the format above and set both environment variables in your Azure Container Apps configuration.

📚 Sources:

1. Transactional Email
2. Support for configuring SMTP email at project level
3. bug: "Missing environment variables for sending membership invitation email" error occurs without adding SMTP variables to docker-compose.yml
4. How to set SMTP_CONNECTION_URL and reset password?

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Have another question? Just tag @inkeep.

[jannikmaierhoefer]

Hi @Mahesh-ai123, was inkeep able to help you with this?

[Mahesh-ai123]

Inkeep couldnt help on the issue @jannikmaierhoefer

[Steffen911]

@Mahesh-ai123 As outlined in our documentation (https://langfuse.com/self-hosting/configuration/transactional-emails) whatever email you configure is forwarded to nodemailer and needs to align with their format: https://nodemailer.com/smtp.
Can you check their documentation page and let us know if any question remains?