RS - open spf tester

It could be a good promotional ad:
“the website is now linked to”

It’s partially true. The link is there, you can check it:

How could that happen?, the original website for the SPF standard, has been down since the spring of 2019.
I tried to contact the old maintainers: Julian Mehnle and Scott Kitterman but got no response.

Sender Policy Framework (SPF) is an old, unperfect, authentication method, available since 2004.
Together with DKIM it still forms the basis of email authentication techniques.
The latest authentication protocol called “DMARC” is actually built around SPF and DKIM.

I needed those information and copy was slow and cumbersome to use.
I downloaded the website locally, using a service called
It didn’t work well right away. The Tunisian developer behind it, provided good paid support and fixed the errors.

A good result: the contents could be browsed with no issues.
It passed the linkchecker validation (you can find this great tool on Github).

Only with the intent to share this valuable resource,
on May 2019 I registered and re-published the old contents.
Google indexed it. Now if you search for “open spf”, it’s the first result.

Some of the “SPF Tools” listed there no longer work,
so I’ve decided to add as well.

It’s very simple, it works well and someone might find it useful.