Wordpress made a change to their default blog mailing infrastructure at the end of 2020.

Due to the updates they no longer send in alignment via SPF. Their instructions may state otherwise, but we have yet to see evidence of alignment from our customers who used the standard/default setup in the past.

Our recommendation is that customers who wish to send via Wordpress as their domain leverage one of the many plugins available in the Wordpress repository. Wordpress themselves also recommend using a third-party host instead of the default service.

We don't have an official recommendation but most customers prefer the plugins which relay out of their corporate infrastructure and can be DKIM signed, or plugins such as "WP Mail SMTP" from WPForms.