And the extent of that parsing should be in accordance with the relevant RFCs (namely, 5322). Per that RFC, the local-part is an opaque string of permitted cha

And the extent of that parsing should be in accordance with the relevant RFCs (namely, 5322). Per that RFC, the local-part is an opaque string of permitted characters. Attempting to parse the local-part beyond that when you ain't the one who owns/controls that address is bug-prone at best and user-hostile at worst.