Saturday DMARC tip: check your subdomains

your main domain might be at p=reject

but what about mail.yourdomain.com?

or marketing.yourdomain.com?

DMARC policies automatically cascade to subdomains (but not all MTA providers respect it!)

you are strongly recommended to explicitly set `sp=reject` in your organizational domain's record

without it, every subdomain inherits p=none by default

https://dmarcguard.io/tools/dmarc-checker/

#DMARC #EmailSecurity #DNSTips #SecurityTip