Does anyone know why an email might get sent without an unsubscribe? Does this mean it may have been sent as operational? We would never send anything without unsubscribe but are wondering potential cases you wouldn't?
In your admin section, double check that the master settings to see if you have Unsubscribe HTML and Unsubscribe Text.
In some cases admins blank these out with and ensure that the links are included in email templates instead.
Also, Operational emails will go to your Unsubscribe list, unless you include that in your filters.
Only Blacklisted emails will not receive an email.
Check out Krewe Chats Week 2: Data Management where we discuss some of these concepts.