I've installed a Debian GNU/Linux server with
postfix+courier-ldap+amavis+clamav.

The server receive 8000 good mail and 150000 spam mail per day.

I have a problem with smtp session.
There are normaly 30 smtp active session and sometimes the client can't send
email.
'SMTP error...'

Server
Dell with 2 Intel(R) Xeon(R) CPU E5310 @ 1.60GHz and 2GB RAM

I insert in Postfix main.cf
smtpd_timeout = 30s
smtpd_recipient_limit = 200

Thanks in advance

--
Roby