For more information on the causes of this issue and the fallout from what turns out to be Debian's changing of the character set for several languages, see the thread "Encoding problem with 2.15 to 2.18 upgrade with Finnish" beginning at https://mail.python.org/pipermail/mailman- users/2015-December/080221.html and continuing at https://mail.python.org/pipermail/mailman- users/2016-January/080275.html. There is a script mentioned in that thread at https://www.msapiro.net/scripts/recode_list (mirrored at http://fog.ccsf.edu/~msapiro/scripts/recode_list) that can programmatically recode the strings in a list's configuration to "fix" this issue.