As someone currently wading through resumes and kinda worried about missing some one like this, here's a tip to anyone else like you: The purpose of a resume is to get you hired. If you have something like an incredible technical sound driver support email chain like that... put a link to it in your resume. Yeah, your resume has standard fields, and those are indeed sorted on by HR, so don't leave out the skills & experience... but otherwise, the resume is free form. Generally not prose exactly, but free form. Link to ANYTHING you think will help you get the job.

And don't just say "I participate in some LUG"... that can mean you show up to the meetings once every couple of months to eat the free food. Show your helpfulness in an email chain. Show a project that you did with them with a link that explicitly says you did a big portion of it. If no such link exists, get one created!

By no means do I promise wonders if you do this. HR filters may still eat your resume. But if you do get through to a real human, they may look at those things, and the ones who will understand what this means are the ones you want to work for anyhow.

If you've got the skills to pay the bills but your resume looks like any other high school dropout's, I can tell you, from the other side of the desk, you've given me no way to tell any different. It may stink that all we have are resumes in the initial process... but at least that resume is under your control. (Mostly. Sometimes it gets chewed on. But speaking for myself, I'm looking at raw resumes straight from the candidate and that's not uncommon.) Don't be afraid to use it, and don't be afraid to toot your own horn, that's the whole point of this particular document.

(Similarly, to the extent possible without lying, don't say "I participated in some project" as your work experience. Write something you did in the project. Don't say "I participated in a billing system upgrade", say how you rewrote the UI in React to conform to accessibility standards and made it run 10 times faster than before and customers uniformly loved it and paid lots more money or whatever. "Participation" could be "I had my hand held for every bug as I struggled to keep up" and it could be "I stepped up and took more responsibility than anyone expected and almost single-handedly completed the project, freeing up the other developers" or anything in between. Unfortunately, based on experience, I kinda have to assume the worst because it's usually right. If "the worst" interpretation of that phrase isn't right, don't leave it open to me!)

Believe me, if you're doing Linux support on a mailing list, or anything even remotely like that, you stand out, at least to the right people. Do whatever it takes to work that on to the resume somehow. The "standard resume form" is a skeleton to be fleshed out, not a straightjacket of form.