Why not use letters and packages which is the literal metaphor these services were built on?
It's like relying on public header information to determine whether an incoming letter or package is legitimate.
If it says: To "Name LastName" or "Company", then it's probably legitimate. Of course it's no guarantee, but it filters the bulk of Nigerian Prince spam.
It gets you past the junk box, but you don't have to trust it with your life.
Why not use letters and packages which is the literal metaphor these services were built on?
It's like relying on public header information to determine whether an incoming letter or package is legitimate.
If it says: To "Name LastName" or "Company", then it's probably legitimate. Of course it's no guarantee, but it filters the bulk of Nigerian Prince spam.
It gets you past the junk box, but you don't have to trust it with your life.
Nuance.