I'm about to attach a patch that adds some virtual host support to mailman. It's not perfect by a longshot but so far works for me. Reproducible: Always
Created attachment 280363 [details, diff] mailman-2.1.13-vhosts.patch patch version number is 2.1.13 but applies cleanly to 2.1.14. Basically mailing list names are now of the format listname-hostname and is based on a patch originally used on some variation of virtualmin (been using it since 2.1.9 and been adjusting ever since). I still USE-flag protect from accidental use due to most people not wanting this patch.
Created attachment 280367 [details, diff] mailman-2.1.14-vhosts.patch Turns out a minor change was required for it to actually work, not sure how I missed that. Code in src_unpack: if use mailvhosts; then epatch "${FILESDIR}/${PN}-2.1.14-vhosts.patch" || die "patch failed." fi I suggest adding an || die to the line just before (ldflags) which is missing.
Created attachment 284639 [details, diff] mailman-2.1.14-vhosts.patch Fixed a minor bug when using bin/config_list to import a list config on a rename from on vhost to another.
We won't support an out of tree patch. I'm aware this is a very old bug, but if you're still interested please try working with upstream.