@mtnsic@nebula.moe Although I subscribed Purism mailing list with Gmail instead of Outlook, there must be something totally wrong with Outlook. I confirmed the mails in the junk box were encrypted with TLS from service.bilibili.com. Some email providers treat unencrypted messages as spam. I can think of no other reason. Maybe it's time to leave Outlook, which sucks.

What's good news, I finally learned how to unsubscribe from Purism mailing list. I couldn't just because I forgot which email address I used. lol