What need users to put in the whitelist of their mailbox to prevent WP generated mails to end up in spam?
Say the server use something like that:
wp_mail( 'email@example.com', 'The subject', 'The message', 'From: My Name <firstname.lastname@example.org>' );
Is it working if users just put 'email@example.com' in the whitelist? Or what should they use?