More missing mail

I’ve reported missing messages in mailing list mode previously; it seems to happen fairly often. Here’s a recent example:

I got Alex’s original question, and then his last message: “Thanks, I’ll give it a go.” But the entire discussion in between is missing for me.

I’ve checked my spam folder, etc. I’ve grepped my mail archive. The text from the missing messages seem nowhere to be found. This has never happened to me on other mailing lists I’m subscribed to.