I noticed that I am getting a number of spam emails that seem to be sent from myself, but when I tried to log into roundcube my log in fails and I am locked out. Since my email still works and logs into roundcube with the same user name and password I don’t know what is going on.
You can use command line to change the user password:
sudo ./mailinabox/management/cli.py user password email@example.com [password]
Other commands available can be viewed by running the command without options: