How to Fix WordPress Not Sending Emails Issue
By default, WordPress uses the PHP mail() function to send emails when required. These can be emails from contact forms, notifications, order confirmations, etc. Many email providers will mark messages sent this way as spam, so these messages may never reach their recipients.
To resolve the problem, you should configure your WordPress to use SMTP instead of the PHP mail() function, SMTP uses proper authentication that leads to high email deliverability. To configure your WordPress to use SMTP, you can follow the instructions in our comprehensive tutorial.
You can also check this videotutorial: