In sendmail.php, some emails will be send with "From:" header being that of commenter's supplied email address, not that of server domain. But if dmarc for mail server has policy quarantine/reject set (recommended for spammer/spoofing control), those emails will be treated as spam or rejected.
In sendmail.php, some emails will be send with "From:" header being that of commenter's supplied email address, not that of server domain. But if dmarc for mail server has policy quarantine/reject set (recommended for spammer/spoofing control), those emails will be treated as spam or rejected.