The problem is that if you send a message just blindly, you can be tricked into sending spam to millions of addresses. I do one thing that prevents that, but does violate the standard, I verify there’s only 1 ‘@’ in the address… this technically prevents people with '@'s in their name, but they probably find it impossible to do anything with that address anyway.
And yet it’s still easy to write spaghetti code in Java. Just abuse inheritance. Where is this function implemented? No one knows but the compiler!