SPF, DKIM, DMARC, MX, and CAA configuration
SPF
18
/25
DMARC
22
/30
DKIM
0
/20
MX
10
/10
CAA
v=spf1 include:_spf.protonmail.ch mx ~all
v=DMARC1; p=quarantine
mail.protonmail.ch.
mailsec.protonmail.ch.