While debugging a SPF record I found
spf-record.de
Show archive.org snapshot
to be very helpful.
- it lists all IPs that are covered by the SPF record
- shows syntax errors
- helps you debugging errors like DNS lookup limit reached
- it also lets you test a new SPF strings before applying it. This can save you time as you don't have to loop with operations
Also the advanced check at
vamsoft.com
Show archive.org snapshot
has a very good interface to test new SPF policies.