DSNs arrived overnight on some of my test messages from rick@linuxmafia.com to the 24 balug-announce subscribers for whom delivery recently got disabled (over high bounce scores).
vdow@unex.berkeley.edu: Delivery attempts will continue star@starshine.org: Delivery attempts will continue luvisi@andru.sonoma.edu: Delivery attempts will continue jtbolton@digizen.net: Delivery attempts will continue cmsclaud@arches.uga.edu: Delivery attempts will continue amcgee@virtualidentity.org: Delivery attempts will continue harpo@thebackrow.net: Delivery attempts will continue danlyke@chattanooga.net: Delivery attempts will continue jason@jcorcoran.net: Delivery attempts will continue kevinchi@tp.silkera.net: Delivery attempts will continue sugo@pescaralug.org: Delivery attempts will continue theeba@cultureisaweapon.org: 454 4.7.1 Relay access denied mhigashi@hooked.net: Delivery attempts will continue mark@gidgetkitchen.org: Delivery attempts will continue travis+ml-balug-talk@subspacefield.org: Delivery attempts will continue ngunther@ricochet.net: Delivery attempts will continue mditter@student.santarosa.edu: Delivery attempts will continue dlym@pop.vox.secureserver.net (generated from dlym@mail.sfpcug.org): Delivery attempts will continue
That's 18 of them. I'll wait to hear about the other six. (Of course, those six may have been SMTP 250-delivered immediately, yesterday. I've not checked my outbound logs, to see.)
Those 18 all seem highly likely to be genuinely undeliverable subscription addresses, but I'll wait for the test attempt to time out. Except, of those 18, "theeba@cultureisaweapon.org" is definitely undeliverable, so I just now removed it from the roster (to clean things up just that little bit more).