Add more logging and ensure that the logs are written. Apply a timeout to all calls such that firewalls and SMTP servers cannot delay SMTP connections. (There are some techniques to delay conversations with spammers forever / for a long time.)
To stabilize the test setup (the first attempt to merge this branch had to be reverted): Use random sockets (and by this ports) generated by a library. Keep the sockets open while the test runs. (Preventing further race-conditions.)
Co-authored-by: fisx <[email protected]>
Co-authored-by: Leif Battermann <[email protected]>