From his contact page:
Letters to Dr. Peterson
For the last year, I have been receiving hundreds of emails a week: comments, thanks, requests for help, invitations and (but much more rarely) criticisms. It has proved impossible to respond to these properly. That’s a shame, and a waste, because so many of the letters are heartfelt, well-formulated, thoughtful and compelling. Many of them are as well — in my opinion — of real public interest and utility. People are relating experiences and thoughts that could be genuinely helpful to others facing the same situations, or wrestling with the same problems.
For this reason, as of May 2018, a public forum for posting letters and receiving comments has been established at the subreddit: Reddit - Dive into anything
If you use the straightforward form at that web address to submit your letter, then other people can benefit from your thoughts, and you from their responses and votes. I will be checking the site regularly and will respond when I have the time and opportunity.
Not sure where that leaves this community… Pity he didn’t team up here as the infrastructure is perfect for it. Bummer.