The MAIL_URL environment variable in Rocket.Chat is used to configure the email settings for sending emails from the Rocket.Chat server. This includes sending notifications, password resets, and other email communications to users. Here’s a detailed guide on how to set up and configure the MAIL_URL environment variable for Rocket.Chat: What is MAIL_URL?

MAIL_URL specifies the SMTP (Simple Mail Transfer Protocol) server that Rocket.Chat will use to send emails. The format for this URL is:

perl

MAIL_URL=smtp://username:password@smtp.example.com:587/

Setting Up MAIL_URL

To configure the MAIL_URL environment variable, you need to specify the SMTP server settings, including the server address, port, and authentication credentials. Here’s a breakdown of how to set it up:

SMTP Server Details:
    Username: Your SMTP server username (e.g., email address).
    Password: Your SMTP server password.
    Host: The SMTP server address (e.g., smtp.example.com).
    Port: The port used by the SMTP server (commonly 587 for TLS or 465 for SSL).
    Protocol: The protocol used for the connection (smtp, smtps, etc.).

Format of MAIL_URL:
    Basic Format:

    perl

MAIL_URL=smtp://username:password@host:port/

Example:

perl

    MAIL_URL=smtp://user:password@smtp.mailgun.org:587/

Steps to Configure MAIL_URL For a Self-Hosted Rocket.Chat Instance

Determine SMTP Server Details:
    Obtain the SMTP server details from your email service provider. This includes the SMTP server address, port, username, and password.

Set the Environment Variable:
    If you are running Rocket.Chat on a Linux server, you can set the MAIL_URL environment variable in your system’s environment configuration.

For a systemd-based service:

    Edit the Rocket.Chat service configuration file (usually found in /etc/systemd/system/rocketchat.service):

    ini

[Service] Environment="MAIL_URL=smtp://username:password@smtp.example.com:587/"

Reload the systemd configuration and restart Rocket.Chat:

bash

sudo systemctl daemon-reload
sudo systemctl restart rocketchat

For Docker:

If you're using Docker, you can set environment variables in your docker run command or in your docker-compose.yml file:

bash

docker run -d --name rocketchat \
  -e MAIL_URL=smtp://username:password@smtp.example.com:587/ \
  rocketchat/rocket.chat

In docker-compose.yml:

yaml

environment:
  - MAIL_URL=smtp://username:password@smtp.example.com:587/

For Rocket.Chat Cloud or Other Hosted Environments

Cloud Instances: If you're using Rocket.Chat’s cloud service or another hosted solution, you may need to configure email settings through the provided administrative interface or support resources rather than setting environment variables directly.

Testing Email Configuration

After setting the MAIL_URL variable, you should test the email functionality:

Send Test Emails:
    Use the Rocket.Chat administration panel to send a test email or try resetting a password to verify that emails are being sent correctly.

Check Logs:
    Look at the Rocket.Chat logs for any errors related to email sending. Logs can provide insights into connection issues or authentication problems.

Troubleshooting

Authentication Errors: Double-check the username and password used in the MAIL_URL to ensure they are correct.
Connection Issues: Verify that the SMTP server address and port are correct and that your server can connect to the SMTP server.
Firewall: Ensure that your server’s firewall allows outgoing connections to the SMTP server’s port.

By configuring the MAIL_URL environment variable properly, you can ensure that Rocket.Chat can send emails for notifications, alerts, and user communications.