Why is my WordPress site not sending password reset or order emails?

WordPress fails to deliver transactional emails when it relies on default server-side PHP mail functions; this is resolved by routing your mail through a dedicated SMTP plugin and provider.

“This is usually WordPress trying to send mail through your server’s default PHP function, which most inboxes distrust. I’ll route it through proper SMTP and have it delivering within 24 hours for $99.”
— Jeff Bollettino, Managing Director, Ignite Conversions