5

What is the difference between

v=spf1 include:_spf.google.com ~all

and

v=spf1 include:spf.google.com ~all

(the first one is with underline character in front of the spf, the second one without)

| improve this question | | | | |
11

spf.google.com doesn't exist, while _spf.google.com contains a valid SPF record.

In other words: only the first line will actually work (as of now).

If you search DNS for _spf.google.com you get the following result:

_spf.google.com IN TXT v=spf1 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com ~all

Google is using the _underscore addresses to hold particular DNS records. There is no particular significance to the character choice; it's just their naming convention.

| improve this answer | | | | |
0

The "include" lets your spf record include another spf record, so it basically just points to a host entry.

The tool at http://www.kitterman.com/spf/validate.html also performs lookup on includes, and will tell you in cleartext that the host spf.google.com does not exist.

| improve this answer | | | | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.