(playfully or maliciously) take your phone and text someone pretending to be you? It doesn't feel very good, does it? Even after clarifying the truth with the recipient, he will probably be suspicious of all your messages in the future. And you'll probably be much more careful who you let borrow your phone. Trust has been broken. A similar scenario is possible in the world of email, and potential phishers don't need your username and password to impersonate your business. Scary, right? Luckily, we know a simple and not-so-secret trick to protect your brand reputation. It's called sender policy framework (spf), and it's a lifeline for email reputation. When email is sent from one server to another, simple mail Transfer protocol (smtp) is used to transmit a message from the sender to the recipient. As an smtp service, twilio sendgrid facilitates this process. A security company mailing list weakness in the email infrastructure is the ability for any sender or host to identify themselves and their email as any domain they wish (much like how people have created tons of donald trump twitter accounts). This makes it difficult for recipients to believe that a message really comes from the person it is supposed to come from. It also makes senders uncomfortable knowing that anyone can send mail from their domain and potentially damage their brand reputation. Recipients lose faith in the authenticity of emails and senders are paranoid imposters impersonating their brand – it's not good for anyone! Part of the solution is the spf record which is stored in a txt record in dns. In this article, we'll explore all things spf Peace of mind knowing that phishers aren't spoofing emails or phishing their audience from their brand. More technically, an spf record is a short line of text that a domain administrator adds to their txt record. The txt record is stored in the dns (domain name system) along with their a, ptr, and mx records. An spf record looks like this:"V=spf1 ip4:12.34.56.78 include:example.Com -all" how fps works the line of text above is used to tell the receiving smtp server which hosts are allowed to send mail from a given domain.