Airflow – Emailoperator Is Not Working – Connection Refused New update

If you are facing a “Connection refused” error while trying to use the EmailOperator in Apache Airflow, it could be due to various reasons such as:

1. Incorrect email configuration: Make sure that you have provided the correct email server configuration details such as SMTP server, port number, username, and password.

2. Firewall or network restrictions: Check if your network has any firewall restrictions that are preventing the connection to the email server. You can try disabling the firewall temporarily or configuring it to allow the connection to the email server.

3. Email server downtime: Sometimes, the email server may be down or undergoing maintenance, causing a connection error. You can check the email server status or contact the email service provider to confirm if there is an issue with the email server.

4. Authentication issues: Ensure that the email server authentication details provided in the Airflow configuration are correct.

To troubleshoot the issue, you can try the following steps:

1. Check the Airflow logs for any error messages related to the EmailOperator.

2. Verify the email server configuration details in the Airflow configuration file.

3. Try using a different email service provider to confirm if the issue is with the email server.

4. Contact the email service provider to get assistance with the configuration.

5. Verify that the SMTP server is accepting connections on the specified port by attempting to connect to it manually using a command-line tool such as telnet.

6. Ensure that the Airflow worker has access to the email server and can connect to it.

7. Check if any changes were made to the network or firewall settings that could be preventing the connection.

To use the EmailOperator in Airflow, follow these steps:

1. Import the EmailOperator:

python
from airflow.operators.email_operator import EmailOperator

1. Define the email settings:

python
default_args = {
    'owner': 'airflow',
    'email_on_failure': True,
    'email_on_retry': False,
    'retries': 1,
    'retry_delay': timedelta(minutes=5),
    'start_date': datetime(2022, 1, 1)
}

email_subject = "Airflow Alert: Job Failed"
email_to = "youremail@example.com"
email_cc = "yourotheremail@example.com"

1. Create an instance of the EmailOperator:

python
email_task = EmailOperator(
    task_id='send_email',
    to=email_to,
    cc=email_cc,
    subject=email_subject,
    html_content='Job Failed, please check the logs',
    dag=dag
)

1. Set the EmailOperator as a task in your DAG:

python
email_task >> next_task

In this example, the EmailOperator sends an email with the subject “Airflow Alert: Job Failed” to email_to with a copy to email_cc. The email’s body contains the text “Job Failed, please check the logs”. This operator is set to send an email only when the task fails, according to the default_args dictionary.

Note that you will need to configure your email settings in your Airflow configuration file to enable the sending of emails.

SMTP (Simple Mail Transfer Protocol) is a standard protocol used for sending email messages over the internet. When an SMTP server receives a connection request from a client, it can either accept or refuse the connection. A refused connection occurs when the SMTP server rejects the connection request from the client.

There are several reasons why an SMTP server may refuse a connection request. Here are some common ones:

1. Authentication failure: The SMTP server requires authentication before it allows the client to establish a connection. If the client fails to provide the correct authentication credentials, the server will refuse the connection.

2. Invalid or blocked IP address: The SMTP server may be configured to block connections from certain IP addresses or ranges of IP addresses. If the client’s IP address falls into one of these categories, the server will refuse the connection.

3. Firewall or network issues: The connection may be refused if there are issues with the network or firewall settings that prevent the client from establishing a connection to the server.

4. Server overload: The SMTP server may refuse connections if it is currently handling too many requests or is overloaded with traffic.

When an SMTP server refuses a connection, it will typically send an error message to the client explaining the reason for the refusal. The client can then take steps to resolve the issue and attempt to establish the connection again.

Setting up SMTP (Simple Mail Transfer Protocol) in Airflow allows you to configure email notifications for task success, failure, retry, and SLA (Service Level Agreement) violations. Here are the steps to set up SMTP in Airflow:

1. Open the Airflow configuration file, which is usually located at $AIRFLOW_HOME/airflow.cfg.

2. Locate the [email] section in the configuration file and configure the following options:

   • email_backend: Set the value to airflow.utils.email.send_email_smtp to use SMTP as the email backend.

   • smtp_host: The SMTP server hostname or IP address.

   • smtp_starttls: Set the value to True if you want to use TLS encryption for the SMTP connection. If your SMTP server doesn’t support TLS, set this to False.

   • smtp_ssl: Set the value to True if you want to use SSL encryption for the SMTP connection. If your SMTP server doesn’t support SSL, set this to False.

   • smtp_port: The SMTP server port number. If you are using TLS or SSL encryption, make sure to use the appropriate port number.

   • smtp_login: The username for authenticating with the SMTP server. If your SMTP server doesn’t require authentication, you can leave this option blank.

   • smtp_password: The password for authenticating with the SMTP server. If your SMTP server doesn’t require authentication, you can leave this option blank.

3. Save the configuration file and restart the Airflow webserver and scheduler.

4. Test the SMTP configuration by running a DAG with email notifications enabled. If everything is configured correctly, you should receive an email when the DAG starts, finishes, or fails.

Note: You can also configure other email-related options in the [email] section, such as the sender address, the recipient addresses, and the email subject and body templates. For more information, refer to the Airflow documentation on email configuration.