Contact form emails can go missing for several reasons: weak mail authentication, poor sender settings, spam filtering, blocked PHP mail, or the form plugin failing silently.
Check the Sender Address
The form should usually send from an address on your own domain. Put the visitor's email in the reply-to field.
Use SMTP
Authenticated SMTP is usually more reliable than basic PHP mail. It also gives clearer logs when something fails.
Check DNS Authentication
SPF, DKIM, and DMARC help receiving servers trust mail from your domain. Missing or incorrect records can hurt delivery.
Test More Than One Inbox
Send test form submissions to different providers. If one provider blocks the mail and another accepts it, deliverability is likely the issue.
Form mail should be tested after migrations, DNS changes, and plugin updates.
