Twitter has begun using a new method called Domain-based Message Authentication, Reporting and Conformance (DMARC) DMARC is a standard for preventing email spoofing, in order to make it harder for attackers to send phishing emails that appear to come from addresses. Twitter says it started using the DMARC earlier this month. AOL, Gmail, Hotmail or Outlook and Yahoo already make use of it. If you don’t use Gmail or one of the other email providers listed above, you may not be protected.
Source: https://thehackernews.com/2013/02/twitter-added-dmarc-support-to-prevent.html