First, I apologise for not noticing that the comments had been broken for a while. This was entirely my fault and not fault of ISSO, which I’m still super happy with as a self-hosted comments system. So in this post I’m going to describe what went wrong, and also how I made the system a little more resilient at the same time.

First, what did go wrong?

My web server is using FreeBSD as its OS, with a bunch of software installed via FreeBSD’s ports system. For those not that familiar with FreeBSD’s ports, the system essentially acts like a rolling distribution. As a result, you sometimes have to upgrade tools, especially languages like Perl, Ruby, and in this case, Python. A little while ago, the default Python version on FreeBSD was upgraded from Python 3.7 to Python 3.8, and I eventually followed along with that upgrade. ISSO is run out of a virtualenv as a regular user and the virtualenv was still using Python 3.7, but I decided I didn’t want to keep multiple Python versions on this machine. So, I upgraded the version in the virtualenv to 3.8 as well. So far, so good, especially as ISSO seemed to restart without issue.

We all love the odd debugging story, so I finally sat down and wrote up how I debugged a configuration issue that got in the way of the iOS mail app’s ability to retrieve email while I was on the go.

tl;dr - iOS Mail uses IPV6 to access you email server when the server supports IPV6 and doesn’t fall back to IPV4 if the IPV6 connection attempt fails. If if fails, you don’t get an error, but you don’t get any email either.

The long story of why I sporadically couldn’t access my email from the iOS 10 Mail app

Somewhere around the time of upgrading my iPhone 6 to iOS 10 or even iOS 10.2, I lost the ability to check my email using the built-in iOS Mail app over an LTE connection. I am not really able to nail down the exact point in time was because I used Spark for a little while on my phone. Spark is a very good email app and I like it a lot, but it turned out that I’m not that much of an email power user on the go. I didn’t really need Spark as Apple had added the main reason for my Spark usage to the built-in Mail app. In case you’re wondering, it’s the heuristics determining which folder you want to move an email to that allow both Spark and now Mail to suggest a usually correct destination folder when you want to move the message.

I still use the mutt email client when I’m remoted into some of my FreeBSD servers. It might not be the most eye pleasing email client ever, but it’s powerful, lightweight and fast.

Mutt has a very powerful feature that allows you to tag messages via regular expressions. It has a couple of special pattern modifiers that allow you to apply the regex to certain mail headers only. I can never remember so I’m starting a list of the ones I tend to use most in the hope that I’ll either remember them eventually or can refer back to this post. The full documentation can be found here, so this is only a cheat sheet that reflects my personal usage of the mutt regex pattern modifiers.