Why I built this
From Diogo Ramos · computer science student, Toronto
Before I went back to school for computer science, I worked as an advisor at Geek Squad. A lot of the laptops that came across the counter had the same story attached. Someone got an email that looked like it was from their bank, or a courier, or “Microsoft”, clicked once, and then we were the ones cleaning it up.
What stuck with me is that these people were not careless. The emails were just good enough, and nobody had ever shown them where to look. I kept thinking I wished I could hand them something that opens the email for them, touches nothing, and says in plain words why it is worried.
So that is what this is. It reads the headers, the route the email took to get to you, whether the sender passed the usual sign-in checks (SPF, DKIM, DMARC), where each link really goes, what each attachment really is, and how the writing tries to rush you. Then it adds it up. The part I care about most is that every single point in the score has a reason sitting next to it, so you can look at the number and disagree with it.
What it can’t do
I would rather say this up front than have you find it. Every email in this mailbox is one I wrote, and I also wrote the checks, so my 34 out of 36 is me marking my own homework. I wrote a second batch after I froze the weights to be a bit fairer to myself, and it still found a miss (the one with the RAR file). It also wrongly flags a security awareness email that quotes a phishing example. It has never seen real mail.
It does not truly verify DKIM signatures, it does not read QR codes, it does not look inside RAR files, and the wording checks only know English. Treat it as a way to learn how this stuff works, not as something to trust with your inbox.
What I would do next
First, get someone else to write the test emails, so I am not both the author and the grader. After that, try it on real mail that people give me permission to use, add real DKIM checking, read QR codes, and open RAR and 7z files the same careful way I already read ZIPs.
Diogo