opqi opened a new issue, #45983:
URL: https://github.com/apache/airflow/issues/45983
### Apache Airflow version
2.10.4
### If "Other Airflow 2 version" selected, which one?
2.10.3
### What happened?
#### Description:
The current implementation of email sending in Airflow does not allow the
`from_email` parameter to function as intended due to the behavior of
`smtp_mail_from`.
The code snippet from send_email_smtp function in airflow/utils/email.py
below highlights the issue:
```python
smtp_mail_from = conf.get("smtp", "SMTP_MAIL_FROM")
if smtp_mail_from is not None:
mail_from = smtp_mail_from
else:
if from_email is None:
raise ValueError(
"You should set from email - either by smtp/smtp_mail_from
config or `from_email` parameter"
)
mail_from = from_email
```
### Issue:
- **`smtp_mail_from` is always a string.** Even if the configuration in
`airflow.cfg` leaves it empty, `conf.get("smtp", "SMTP_MAIL_FROM")` defaults to
an empty string (`""`), which is not `None`.
- As a result, the `from_email` parameter is **never used** because the `if
smtp_mail_from is not None` condition is always `True`.
- This behavior renders the `from_email` parameter in various email-related
functionalities effectively useless.
### What you think should happen instead?
### Expected Behavior:
The `from_email` parameter should take precedence if explicitly provided,
but it currently cannot because `smtp_mail_from` is never `None`.
### Proposed Solution:
Modify the condition to properly handle empty strings and prioritize
`from_email` when explicitly set:
```python
smtp_mail_from = conf.get("smtp", "SMTP_MAIL_FROM")
if smtp_mail_from: # Check for non-empty string
mail_from = smtp_mail_from
else:
if from_email is None:
raise ValueError(
"You should set from email - either by smtp/smtp_mail_from
config or `from_email` parameter"
)
mail_from = from_email
```
This change ensures:
1. `smtp_mail_from` is only used when it is explicitly set to a non-empty
value.
2. The `from_email` parameter is respected when provided.
### How to reproduce
#### Prerequisites:
- An Airflow instance is running.
- Access to the Airflow UI to create an SMTP connection.
---
#### Steps to Reproduce:
1. **Clear SMTP Configuration in `airflow.cfg`:**
In the `airflow.cfg` file, ensure all SMTP-related parameter in the
`[smtp]` section are left blank or commented out:
```ini
[smtp]
smtp_mail_from =
```
2. **Restart Airflow:**
Restart the Airflow services to apply the changes:
```bash
airflow scheduler restart
airflow webserver restart
```
3. **Create an SMTP Connection in the Airflow UI:**
- Navigate to the **Admin** -> **Connections** page.
- Click **+ Add a new record**.
- Fill out the connection details:
- **Conn Id**: `smtp_test`
- **Conn Type**: `SMTP`
- **Host**: `<SMTP server>` (e.g., `smtp.example.com`)
- **Port**: `25`
- **Email From**: `[email protected]`
- Leave other fields empty or as defaults.
- Save the connection.
4. **Create a DAG with an `EmailOperator`:**
Use the following sample DAG to send an email:
```python
from airflow import DAG
from airflow.operators.email import EmailOperator
from datetime import datetime
with DAG(
dag_id='test_smtp_from_email',
start_date=datetime(2025, 1, 1),
schedule_interval=None,
catchup=False,
) as dag:
email_task = EmailOperator(
task_id='send_email',
conn_id='smtp_test',
to='[email protected]',
subject='Test Email',
html_content='This is a test email.',
from_email='[email protected]', # Explicit from_email
)
```
5. **Trigger the DAG:**
- Navigate to the Airflow UI.
- Trigger the `test_smtp_from_email` DAG.
---
#### Expected Behavior:
- The email should be sent with `[email protected]` as the `From`
address when `from_email` is explicitly provided.
---
#### Actual Behavior:
- The email is sent using the default `smtp_mail_from` from `airflow.cfg`
(likely an empty string or a misconfigured value).
- The `from_email` parameter is ignored completely.
---
This demonstrates that the `from_email` parameter is not respected due to
the logic prioritizing `smtp_mail_from`, even when it is blank.
### Operating System
Debian GNU/Linux
### Versions of Apache Airflow Providers
_No response_
### Deployment
Docker-Compose
### Deployment details
curl -LfO
'https://airflow.apache.org/docs/apache-airflow/2.10.3/docker-compose.yaml'
### Anything else?
### Impact:
This bug impacts all email-sending functionalities, such as email alerts,
`EmailOperator`, and any custom email utilities relying on Airflow's email
sending methods.
### Environment:
- Airflow version: 2.10.3
Let me know if more details or examples are needed!
### Are you willing to submit PR?
- [x] Yes I am willing to submit a PR!
### Code of Conduct
- [x] I agree to follow this project's [Code of
Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
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