It can be frustrating after doing all the hard work of creating your WordPress website that all your outgoing emails end up in your customers spam or junk folders. This is a very common issue with websites built with WordPress and can lead to important messages not being received or you could even lose sales because quotes or reminders are not seen.
The best way we have found to help you with this issue is the Stop WP Emails Going to Spam plugin which can be found here – https://wordpress.org/plugins/stop-wp-emails-going-to-spam/
WordPress uses a PHP mailer as default and this often leads to email clients automatically thinking it is spam no matter how important or trustworthy the email actually is.
If you use an SMTP email plugin or use an API based transactional email plugin, this plugin will add no value; it is built to support the default PHP mailer only.