Unable to Send Emails Using Flask-Mail with Mailtrap SMTP Server

[synetalsolutions]

Description:
I am encountering an error when attempting to send emails using Flask-Mail with Mailtrap SMTP server configured in Docker-compose.yml. The error message indicates a problem with the sender address syntax.

Traceback (most recent call last): File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner self.run() File "/usr/lib/python3.8/threading.py", line 870, in run self._target(*self._args, **self._kwargs) File "/app/app/email.py", line 8, in send_async_email mail.send(msg) File "/usr/local/lib/python3.8/dist-packages/flask_mail.py", line 492, in send message.send(connection) File "/usr/local/lib/python3.8/dist-packages/flask_mail.py", line 427, in send connection.send(self) File "/usr/local/lib/python3.8/dist-packages/flask_mail.py", line 188, in send self.host.sendmail(sanitize_address(envelope_from or message.sender), File "/usr/lib/python3.8/smtplib.py", line 880, in sendmail raise SMTPSenderRefused(code, resp, from_addr) smtplib.SMTPSenderRefused: (501, b'5.1.7 Bad sender address syntax', 'api')

Steps to Reproduce:

1. Configure Mailtrap SMTP server in Docker-compose.yml.
2. Use Flask-Mail to send emails in your application.
3. Trigger an email sending action.

Expected Behavior:

Emails should be sent successfully through the configured Mailtrap SMTP server without any syntax issues.

Actual Behavior:
Encountering a syntax issue with the sender address, leading to the failure of email sending.

Additional Information:

Flask-Mail version: [Insert Flask-Mail version]
Python version: [Insert Python version]
Docker-compose.yml configuration for Mailtrap SMTP server.

Note:
I have ensured that the sender address is correctly formatted, and I've tested the SMTP server configuration outside of Flask-Mail, which works fine. This issue seems specific to Flask-Mail interaction with Mailtrap.

Any insights or suggestions on resolving this issue would be greatly appreciated.