DMARC - Rejection Emails

What is DMARC?

DMARC standardizes how email receivers perform email authentication using the well-known SPF and DKIM mechanisms. This means that senders will experience consistent authentication results for their messages at AOL, Gmail, Hotmail, Yahoo! and any other email receiver implementing DMARC.
 

How am I affected?

If you utilize a form on your website which has visitors send an email using a 'FROM' field in which they input their email addresses, there is a chance that the email will fail due to authentication if DMARC is being used by the @domain.com address. As of this writing, this only affects @yahoo.com addresses, however this may change in the future.

What can I do to fix this?

We recommend that you update the 'FROM' field within your form to use an email address of @example.com. Additionally, the 'REPLY-TO' setting can be used with any DMARC compliant address and will successfully send emails without rejection such as @yahoo.com, @hotmail.com, @gmail.com, or @aol.com.

An example can be seen in the following header:

$headers = 'From: user@example.com' . " " .
'Reply-To: user@yahoo.com' . " " .
'X-Mailer: PHP/' . phpversion();