How to protect against spoofing and phishing

Problem

How can you protect against spoofing, phishing and help prevent messages from being marked as spam.

Environment

  • Gmail
  • Email authentication

Solution

You must add or update your record.

Important:

  • Configure DomainKeys Identified Mail (DKIM) and Sender Policy Framework (SPF) before configuring DMARC. DKIM and SPF should be authenticating messages for at least 48 hours before turning on DMARC.

  • The domains used in the steps below are examples only. Replace these example domains with your own domains.

Make sure to apply these steps in the management console for your domain host, not in the Admin console. Who is my domain host?

  1. Have the text file or line that represents your policy record ready.
  2. Sign in to the management console for your domain host.
  3.  Locate the page where you update DNS records.
  4. Add a DNS TXT record, or modify an existing record, by entering your record in the TXT record for  _dmarc:
    • TXT record name: In the first field, under the DNS Host name, enter: _dmarc.example.com
    • Important: Some domain hosts automatically add the domain name after _dmarc. After you add the TXT record, you can verify the DMARC TXT record name to make sure it's formatted correctly.
    • TXT record value: In the second field, enter the text for your DMARC record, for example:
  5. v=DMARC1; p=none; rua=mailto:dmarc-reports@example.com
  6. The field names might be different for your provider. DNS TXT record field names can vary slightly from provider to provider. The domain used here is an example domain. Replace example.com with your own domain.
  7. Save your changes. 

Cause

  • Emails being sent from third party server, spoofing domain.
  • Checked one of the message headers affected.
  • Found the email is coming from a third party server.
  • SPF and DKIM failing, domain already has these 2 authentication added .