The process I started with For my sins and documented my progress with Progress and Regress is now officially (probably) done. Mailman is up and running, mail is being delivered (although as usual, only one of my lists is getting much traffic). The new archives are very cool, with full text and all. I actually had to deal with a Y2K bug – some of the mail in the old archives had the year as “number of years after 1990” instead of “number of years after 0”, which meant I had to fix a bunch of dates with years 100, 101, and in the case of one person who refused to upgrade, 102 and 103. And I even put the websites behind https using the brilliant mod_md, which is even easier to use that certbot, which is what I’d used on some other domains.
I shut down my old linode, but just in case I need to recover something from it in the near future, I haven’t deleted it yet. Linode.com still charges the same rate for shut down servers as active ones, but it’s only by shutting it down I can make sure there isn’t something still relying on it that I forgot.