The “PermError” error means the published SPF record could not be verified by the mailbox provider. PermErrors are usually caused by a syntax or format error in the SPF record.
To fix the SPF Permerror, verify the SPF record for your “From” email domain and for the “Return-Path” email domain to ensure your SPF records are set up correctly and don’t have any extra spaces or unrecognizable characters in the DNS TXT records.
You can use the GlockApps free SPF record checker to verify the SPF record.
Read more:
Everything that Causes an SPF Fail
What is SPF Record: How to Create, Optimize and Check It