TSQL - Extraer correo electronico de un texto

fnExtraerEmails.sql

CREATE FUNCTION [dbo].[fnExtraerEmails] (@email varchar(255))
	RETURNS VARCHAR(255)
	AS
	BEGIN

		declare @Izda varchar(255);
		declare @RevIzda varchar(255);
		declare @Dcha varchar(255);
		declare @resultado varchar(255);

		SET @Izda = LEFT(@email, CHARINDEX('@', @email, 0) - 1);
		SET @RevIzda = REVERSE(LEFT(@email, CHARINDEX('@', @email, 0) - 1));
		SET @Dcha = RIGHT(@email, LEN(@email) - CHARINDEX('@', @email, 0) + 1 )
	
		SET @resultado = 
			REVERSE(
				SUBSTRING(@RevIzda, 0, 
					CASE
						WHEN PATINDEX('%[' + CHAR(10)+'- ]%', @RevIzda) = 0 THEN LEN(@RevIzda) + 1
						ELSE PATINDEX('%[' + CHAR(0)+'- ]%', @RevIzda)
					END
				)
			)
			+
			SUBSTRING(@Dcha, 0,
				CASE
					 WHEN PATINDEX('%[' + CHAR(0)+'- ]%', @Dcha) = 0 THEN LEN(@Dcha) + 1
					 ELSE PATINDEX('%[' + CHAR(0)+'- ]%', @Dcha)
				END
			)
	
		RETURN @resultado
	END
GO