Uit De Vliegende Brigade
DMARC is een broertje van SPF en DKIM en is eveneens een middel tegen spam. :
Another application for TXT is the DMARC record. This type of record can be used to indicate that emails are protected by SPF or DKIM and tells the receiving mailserver what to do if none of these methods succeed. This type of record is an extra security measure but is not used very often. Check out this page for more information on DMARC.
A DMARC policy allows a sender to indicate that their messages are protected by SPF and/or DKIM, and tells a receiver what to do if neither of those authentication methods passes – such as junk or reject the message. DMARC removes guesswork from the receiver’s handling of these failed messages, limiting or eliminating the user’s exposure to potentially fraudulent & harmful messages. DMARC also provides a way for the email receiver to report back to the sender about messages that pass and/or fail DMARC evaluation.
Dit lijkt de standaard-waarde voor DMARC te zijn voor TransIP:
v=DMARC1: Dit zal wel de versie van het protocol zijn
p=non: : This is the least restrictive setting. You’ll still get email reports if there’s an issue with your DNS, but it’s unlikely to affect your own emails from being delivered. If you start to get suspicious DMARC reports, you could change this part of the rule to