How to verify when/if RAM sent an email per lifecycle policy?

There is no log of email that was successfully sent. The log would contain SMTP server errors. But typically if an email can't be sent due to SMTP server errors the email is queued up until SMTP is working again. As soon as SMTP is working then all queued mail, starting with the oldest, will be sent.

You can test if the user has a valid email by going to some asset, and select the "mail" icon in the upper right. Then type in the user's name to get his entry and send a message. If he receives it then his email is registered correctly.