Update (April 2018): Apple appear to have fixed this in late 2016 - see this article from feed.press. Two podcasts I run have disappeared from the iTunes podcast store. After a few baffling evenings spent debugging a rather frustrating “Can’t read feed” error, it turns out the problem is fairly simple. The iTunes Store’s support for SSL is a bit disappointing, to say the least. To get a podcast into the iTunes store, you need to make sure your SSL set-up is supported by Java 6.
I’ve started using Let’s Encrypt a lot, for all my domains in fact. Previously, I’ve been using letsencrypt-auto, and stopping my webserver every time I want to renew a certificate. This is probably fine (all the sites and domains I run are low traffic, and can afford to be down for 30s or so when certificates need renewing every few months), except a flaw in my process for renewing certificates meant I took my webserver down for 12 hours or so.