GROUP BY and LIMIT AND COUNT(*) query simultaneously

Question

I want to extract top 5 poster's email and its post count in my board application.

for example, this is my board table schema. | email | title | content |

And following SQL gives me every people's email who posted in my board and their post count.

SELECT email, COUNT(*) FROM myboard GROUP BY email ORDER BY COUNT(*) DESC;

|  email  | COUNT(*)|
---------------------
| a@a.com | 20      |
| b@a.com | 17      |
| c@a.com | 11      |
...

I want limit only top 5 poster. In MYSQL Limit 0, 5 works well, but Oracle does not have LIMIT query.

So how can i do it in the Oracle?