SPF contains an unrecognised modifier
NOTEWhat it means
the offending value is not a modifier any receiver acts on. The standard says to ignore it, so it is harmless, and it is usually a typo for redirect= or exp= that someone believes is working.
How to fix it
Remove the offending value, or correct it if you meant redirect= or exp=.
Check your own domain
This page describes the condition. To find out whether your domain has it, run the SPF test or the full checkup, which examines every record at once.
Understand it properly
This page covers one condition. For the whole picture, What is SPF, and the ten-lookup limit, or start at the Health Library.
Where this comes from
We judge this against RFC 7208 section 6. Every finding on this site cites the specification behind it so you can check the work rather than take our word for it.
Other SPF conditions
SPF_UNKNOWN_MODIFIER
Every fix on this site is yours to implement. If you would rather someone did it, I take this work directly.