Resolution: Not A Defect
Jenkins Version 2.32.3
Email extension plugin 2.57.1
I see that some security was added so that emails don't get sent to people that shouldn't get emails. I had fixed this by using a pre-send script that filtered out email addresses. However now with the new change, emails are not getting sent at all. I use the unix database backend for my Jenkins system. If I goto the People page I see 2 entries for myself, one as "Jon Schewe" with an email address "firstname.lastname@example.org". I see a second one as "user1" (which is my unix username) with email address "email@example.com". If I setup a job to send email to "firstname.lastname@example.org" I get the error that the email will not be sent to unregistered users. If I send an email to "email@example.com", then it works. Note that I've set "domain2.com" as my default email suffix.
So the first question here is what is a registered user when using the unix database backend?
Second, what is considered the email address for a registered user when using the unix database backend?