recursive-clients, what value ?

[Mikael]

Thanks for all your comments.
Actually, my problem is a bit deeper :
I got lots of those "quota reached" logs : 170 during 6 hours.
And my main problem is that my server got completely frozen and did not 
accept any login until I rebooted it...
Whether it's the cause or the consequence of the freeze, that's what I'm 
trying to find out... Any idea about that ?

Mikael