1. Login into your WordPress admin portal via domain.com/wp-admin
2. Navigate to Add New under Plugins
3. Look for SMTP plugins such as SMTP mailer (https://wordpress.org/plugins/smtp-mailer/) or
WP Mail SMTP (https://wordpress.org/plugins/wp-mail-smtp/)
4. Once it has been install, may navigate to the plugin settings from Setting (In my case, I will be using SMTP mailer)
5. You would need to ensure that the SMTP username is a legit/valid email on your hosting.
6. Basic settings will be as below:
NOTE: The above method/setting shall be only workable with Exabytes mail server and not referring to external mail server.