1. Login in to 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 or 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: