This morning I received notification that an email of mine was found in one of the leaked collections of accounts that are consolidated by the excellent service “haveibeenpwned.com”
When I checked the details, one of the addresses concerned was one that I had generated and provided only to nintourhistory (I generate new unique email addresses for every web service I sign up to; that way I can individually block them and also track where my data is going)
Unfortunate I believe that the most likely explanation is that the nintourhistory account database has been leaked/compromised/stolen. The collection that has that data within it is this one :
https://haveibeenpwned.com/PwnedWebsites#Collection1
If you had provided personal data to nintourhistory consider changing any shared passwords (and then get a password manager like 1Password and stop reusing passwords).