Outlook is extra bad. It is apparently possible to put your email(to/recipient) in BCC, so if you have aliases, it is impossible to tell, which one was leaked a

Outlook is extra bad. It is apparently possible to put your email(to/recipient) in BCC, so if you have aliases, it is impossible to tell, which one was leaked and being abused, as to is marked as “undisclosed recipients”. There is no mass domain/pattern block rules, so if I block “spammer.1@hotmail.com”, then next day it arrives from “spammer.01@hotmail.com”, then blocking that, next day it arrives from “spammer.001@hotmail.com”. Outlook is actively hostile to blocking spams yet happy to quickly block small self-hosted operators.