PTR checks the domain IP address to validate sender address.
But against what? the SMTP HELO hostname?
Or against email domain?
for example if I send an email from
firstname.lastname@example.org from a SMTP server with domain
Is PTR check performed for
Shared Hosting panels(e.g. CPanel) documentation says only set PTR for hosts main domain and not for every vhost.
in this case checking against email's domain will fail But this also means anyone can send email for any vhost (also vhosts which are not on my NS) if their server has correct PTR for itself but not for vhost