I had made an email graphing tool early in my career. The idea was to find instances where an account had sent to and received from an email from any address an

I had made an email graphing tool early in my career. The idea was to find instances where an account had sent to and received from an email from any address and put that in some funnel. The tech worked, I created lovely graphs of conversations but it was far more rare to find hits than expected. I came to find that almost nobody was sending and receiving emails from external domains. (I also discovered I did not want to know what people were doing with their work email.) I eventually did figure out the issue. People use aliases for external communications to protect their inbox and create rules around it. Two or more email addresses per account is quite common. This was a lot harder to solve. Not because I couldn’t create that mapping technically, but because I had to go out and collect everyone’s aliases through user input. So I’ll add that email addresses correspond to unique accounts.