Matwey, your DKIM signature is garbage, and it causes your emails to be marked as spam when they go through a mailing list. The reason is this: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id; where the problem is that the "sender" field is included in the DKIM hash calculation. That is completely incorrect, since a mailing list will - by definition - change the sender to the list, not the original sender. This is not a mailing list bug. This is a bug in your DKIM setup on the sending side. I'm leaving everybody cc'd., because this problem is starting to be annoyingly common. We had two people with chromium.org addresses with the same misconfiguration, and I want people to be aware of this. I get too much email, and too much spam, and so when people have misc-onfigured email sending that causes problems for spam systems, it needs to get fixed. Your situation *may* be the same as the Chromium guys. Quoting Doug: "Looks like it's all fixed. Both Kees and I setup our chromium.org accounts a long time ago. IIRC during that time the suggested way to do things was that you'd use your @google.com SMTP settings even when you were sending as your @chroumium.org account. These days it doesn't appear that there's even any UI in gmail to configure things that way, so presumably nobody else will be stuck in the same hole that Kees and I were in" and he may have been wrong about that "presumably nobody else will be stuck in the same hole" guess. So you might want to check what the SMTP settings are for your setup. Linus