A previous commit broke the smtp authentication using a TLS certificate
and we only figured it out after that a client created a support ticket
several weeks later. It turns out that there are no tests that validate
the various ways outgoing mail servers can be configured.
In this work, we add a test suite where a local smtp server is started
and controlled during the test execution. This makes it possible to test
all the possible outgoing mail server configurations, including TLS.
This work revealed several problems that have been sorted in other PRs,
a problem that is left to solve is to verify those certificates as shown
by the `test_man_in_the_middle` test. This will be sorted in a future
work.
We chose [aiosmtpd] which is a pure-python lightweight SMTP server that
aims at providing a programming API that is well-suited to be used
inside unittests.
task-3703209
opw-3640374
[aiosmtpd]: https://aiosmtpd.readthedocs.io
Part-of: odoo/odoo#151483
Julien Castiaux
3b493f5631