Spam-mail

Emails end up flagged as spam when they meet criteria that makes them look like spam. So it’s up to you to make sure that they don’t look like spam.

Some things you can do:

• Configure your email to go through an SMTP account – this makes it a legitimate email and this solves many email problems. You can do it with a plugin, or a simple code configuration.
• Set the “from” and “from name” to actual email addresses. The plugin’s settings allow you to do this for emails from the plugin. Or use wp_mail_from and wp_mail_from_name filters.
• Set your email return path to be the same as your from address.