Why is email from my WordPress site going to spam.

The quick answer is, there is no quick answer. But there is a quick way to find out.

  1. Install or activate the WP Mail Logging plugin.
  2. Go to https://www.mail-tester.com/
  3. Now register a new user to that email address in WordPress. Usually I just call it spam tester.

That should generate a new user email to the test address. It also will save a copy of the email in your admin console under "Tools -> Mail Logging".

Now on the mail tester site, you will get a full report on the deliverability of the site generated email.

Send additional email

To send additional emails, you can generate those using a WordPress plugin that allows you to email a user, for example

https://wordpress.org/plugins/email-users/

Note that last plugin is now listed as "abandoned", although still works fine
for testing purposes. But we recommend you delete it when you are finished.

This is a free tool, with no usage limits:

https://analyze.email/

Most likely culprits:

  • misconfiguration of the WordPress host
  • missing reverse DNS
  • missing SPF records in the from: address' DNS.