extrar cantidad de registros diferentes

[Libras]

Podria hacerse de esta manera:

Código SQL:

SELECT  completo FROM(
SELECT SUBSTRING(correo,1,INSTR(correo,'.')+1) AS completo FROM(
SELECT SUBSTRING(email, INSTR(email,'@')+-, lenght(email)) AS correo FROM tabla
) AS t1 
) AS t2 WHERE completo='outlook' LIMIT 2;
UNION ALL
SELECT COUNT(*), completo FROM(
SELECT SUBSTRING(correo,1,INSTR(correo,'.')+1) AS completo FROM(
SELECT SUBSTRING(email, INSTR(email,'@')+-, lenght(email)) AS correo FROM tabla
) AS t1 
) AS t2 WHERE completo<>'outlook' LIMIT 1;