Flask-Mailing is the ultimate solution for sending emails asynchronously in Flask applications. With its extensive features such as support for multiple email providers, file attachments, customizable templates, and encryption, Flask-Mailing makes email communication effortless and efficient.
There is an issue in flask-mailman package issue list opened by @pelika. Code sample is from flask-mailing package and should be checked.
https://github.com/waynerv/flask-mailman/issues/37#issue-1268145506