DMARC handling comparison for multiple email providers. SPF passing for all messages. DMARC misaligned.

Gmail

p=none (inbox) p=quarantine (spam)

Gmail shows a very prominent warning for quarantined emails, which go to the spam folder. Emails with no policy are placed on the inbox with no warnings.

Yahoo!

p=none (inbox) p=quarantine (spam)

Yahoo! just places the quarantined email in the spam folder. Other than that there's no difference, no warnings.

Outlook

p=none (inbox) p=quarantine (spam)

Outlook just shows the same little warning it does for any junk email.

ProtonMail

p=none (inbox) p=quarantine (spam)

ProtonMail shows a prominent warning for quarantined e-mails. The warning for p=none seems unrelated with DMARC, they just thought the e-mail was suspicious (well, it was).

Tutanota

p=none (inbox) p=quarantine (spam)

Tutanota also displays a prominent warning saying you should not trust the contents of the message.

All tested email providers sent p=quarantine to spam and p=none to the inbox.

Tutanota, ProtonMail and Gmail place a warning that will probably make a user think twice before trusting the email.

Outlook and Yahoo! show no specific warnings.

Regarding reporting: I received DMARC reports only from Google and Yahoo!. Other providers did not report.