Many clients have troubles with mail configurations and troubles with deliverability / spam this days.

Very usually sending email on servers doesn’t work by default with mail function this days, that’s why you need to use SMTP config.

We suggesting to use smtp email configuration also to reduce failure email delivery.

Very important is to have quality cpanel hosting to archive this properly.

Suggested hosting services found here: https://wpdirectorykit.com/wp/directory-hosting/