SPF Tool and IPv6 Updates

SPF Tool and IPv6 Updates

To continue our support of Email Delivery and Deliverability, MxToolbox is adding IPv6 support (Internet Protocol Version 6) to our SPF Tool, with more tools to come online later. When a user runs an SPF lookup, this update changes the lookup behavior for MX and A records that are specified within an SPF record (as tags).  Now,  SPF lookups will also check for AAAA DNS records and their resulting IPv6 addresses. Previously, the SPF tool only looked for IPv4 addresses when MX and A tags were present in an SPF record.  

Background

IPv6 is the most recent version of the Internet Protocol—the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Web. It was ratified as an Internet Standard in 2017 and allows for larger addressing space. Every computer, smartphone, and any other device connected to the Internet needs a numerical IP address in order to communicate with other devices. Compared to its predecessor, IPv6 can handle packets more efficiently, improve performance, and increase security.

While, IPv6 has been around for decades, IPv6 addresses are now being actively used in email delivery.  MxToolbox is here to help with the transition to IPv6.  MxToolbox’s research of the current outbound email space shows that adoption has largely been among the free webmail providers such as Gmail and Outlook.com.  Additionally, 25% of the Alexa Top 1000 websites are currently reachable over IPv6 networks.

1 https://www.worldipv6launch.org/measurements/