[MM3-users] Re: Uncaught runner exception: 'str' object has no attribute 'decode'

The bottom line is at this point, <https://bugs.python.org/issue27321> no longer affects Postorius, but it still affects message delivery. I have opened <https://gitlab.com/mailman/mailman/issues/406> about defending against that and also the UnicodeEncodeError you included in your OP.

Is there some kind of workaround, I can give my users or something that the list admins can do as a workaround?

No. 'bin/mailman queue' is the Mailman 3 command. The Mailman 2 command is 'bin/show_qfiles'.

I much be in the wrong place because when I do a 'docker exec -it mailman-core bash' and do a 'mailman --help' I don't see a 'queue' argument. The only bin/mailman I have inside the mailman-core container is /usr/local/bin/mailman, which is the same command.