Masterpress 1.3.6 is a compatibility release. It resolves an edge case with shared fieldsets not working for MySQL 8 when the fieldset is limited to more than 1 post type or taxonomy or excluding any post types or taxonomies.
MPFT :: is_email()
- Boolean true if the value is an email, false otherwise.
Checks if the field value is a valid email address, via WordPress’ is_email function.