DMARC – Policy set to Quarantine

Since February 2015, we have received a little more than 200 error reports from DMARC implementing mail servers including Google, Hotmail, LinkedIn, Microsoft, Yahoo!. Reports are now published on  https://harsha.mobi/dmarc/ and importantly there are two particular organisations misconfigured to send emails as if they are from Harsha.COM mail servers.

To improve this situation, we have upgraded our DMARC policy from “none” to “quarantine”. This means, DMARC implementing servers have option to filter out “forging” mails.

What is DMARC ? It’s a simplified method for participating email servers to determine if an incoming email is valid or a forged email address. For example, if server mail.example.com is trying to deliver email from user@example.com, it is valid. if mail.example.com is trying to deliver user@bad-example.com then it might be a forged address, just by reverse looking the domain name. This gets complicated when mail.example.com also authorised to send bad-example.com but not for good-example.com. Such authorisation are configured via SPF, DKIM and DMARK. A DMARK enabled servers like hotmail.com will verify example.com’s DMARC records. If email address and DMARC records supported with SPF and DKIM are valid, then email will pass through, otherwise email will be considered as “forge” and mail filter policies will apply. Email servers at harsha.com is participating in DMARC syndicate.

Visit http://dmarc.org for more information.