I currently follow a few Debian mailing lists by scanning the list archives instead of being subscribed. I find that makes it a lot easier to not read everything and to resist the temptation to reply.
I've also started following the linux-kernel mailing list, which has anywhere between 100 and 600 posts per day (and next to no spam). First through the archives at lkml.org; later I tried subscribing but that resulted in drowning in mail and some issues with the "ignore/watch threads" option in kmail made me unsubscribe again after a few days. I ended up subscribing to the linux.kernel news group instead, which works well as it's quite easy to tag threads 'ignore' and filter out ignored threads.
In both cases the problem was that sometimes you do want to reply to a post, but how to do that without breaking the thread? My news reader is not smart enough that I can tell it to use the original mail headers, and for the list archives a solution is even less obvious.
So I wrote a little script that allows me to just paste the subject and headers of a post directly from the Debian list archives. For the kernel list I configured my news reader to display some of the original mail headers, so I can also just paste those.
The script will then parse the pasted info and generate correct Subject, To, CC, In-reply-To and References headers. With a few extra lines of code it even generates correct replies to bug reports. After that the script just calls 'mail' with the correct options which asks me to type/paste the body of the mail. Problem solved.
So, just in case D-I colleagues were wondering if maybe I'd resubscribed to the d-boot list, the answer is "no".