Its "is_valid_syntax" result seems to be taking shortcuts and defaulting to "false" for anything not common. Reality is much more complicated: https://stackove

Its "is_valid_syntax" result seems to be taking shortcuts and defaulting to "false" for anything not common. Reality is much more complicated: https://stackoverflow.com/questions/2049502/what-characters-are-allowed-in-an-email-address https://stackoverflow.com/questions/2049502/what-characters-...