You can change the corresponding failregx so it matches successful and failed logins.
Change
Code:
failregex = LOGIN FAILED, .*, ip=\[<HOST>\]$
to
Code:
failregex = LOGIN , .*, ip=\[<HOST>\]$
In the next step change maxretry and maybe the action for the jail.
After reloading the jail, fail2ban triggers on both login-types.
If you have problems with outbound spam,you should check your system instead of using f2b as a workaround.