I subscribed long ago to some Mozilla mailing lists, and forgot which address I used to subscribe. My email account, which is a corporate one on Outlook 365, has several aliases and a few domains.
I cannot find my email addresses (or aliases) or even the domains of my email addresses in the mail headers.
The closest thing in the process of searching for a solution was in an answer to a similar question asked more than nine years ago here (Gmail: How do I know which address this mailing list email is sent to?), where the answer said that the
Delivered-To header would show the address that the mail was sent to. In my case though, the
Delivered-To header only shows the address related to the mailing list sender (like firstname.lastname@example.org).
I have also decoded the entire raw headers using MXToolbox, but that didn't provide anything new.
The mailing list subscription site does not have ways to discover this since I no longer have the original emails from when I subscribed.
So how does one go about figuring which email address the email was sent to from the mailing list? Could there be some header manipulation going on with Outlook 365 where this information has been removed before delivery to the mailbox? Any pointers would be appreciated.