I am an experienced software engineer, and I maintain several different types of Ecommerce websites for clients. I am having the exact same issue with my Woo Commerce websites, since the last update. This mail tracking plugin mentioned does not track any email sent by Woo commerce for lost passwords. Please note that there are more than one lost password page. One for WordPress, and one for Woo Commerce. The woo commerce lost password link does not send any password reset emails to any of our customers and admins. I have even tested this myself. Currently, my admins are locked out of managing their online stores.
I installed the mail tracking plugin, and nothing shows up even after testing the lost password link. I have nothing wrong with my hosting, and I can send email easily via a little bit of PHP code for some of my forms. I believe the Woocommerce plugin is broken.
We are scrambling to get our clients passwords manually reset and back into their accounts. This has been going on most of July 2018.
Thanks.