mailman list names are supposed to be lowercase only.
we have this one though:
when trying to import it on fermium, we get:
<mutante> ==> /var/log/mailman/mischief <==
<mutante> Aug 15 02:14:58 2015 (3431) Hostile listname: wikitech-announce.disabled.T100503
so we should just rename it. we are supposed to keep it but leave it disabled.
remove the "T" in it or the entire "T1000503" part.