[Dovecot] Dovecot problem in RHEL4

[~adarsh~]

Hi all,
 i am not able to sort out the connection dropping issues by the IMAP
dovecot.it coours frequently within 2 or 3 hours. Iam using
squirrelmail clent.
I have 100 users using Imap (no pop3). Can any body suggest the
suitable configuration.
My config file looks like .


protocols = imap imaps
imap_listen = [*]

login_dir = /var/run/dovecot-login
login = imap
log_timestamp = "%Y-%m-%d %H:%M:%S "
login_process_size = 256
login_process_per_connection = no
login_processes_count = 15
login_max_processes_count = 900
max_mail_processes = 4096


default_mail_env = maildir:/home/Mails/%u/Maildir
mbox_locks = fcntl
auth = default
auth_mechanisms = plain
auth_userdb = passwd
auth_passdb = pam
auth_user = root

Any points to solve this issues.
I am using dovecot-0.99.11-2.EL4.1 on RHEL4

-- 
Adarsh
"Unless you change direction, You are likely to arrive at where you are headed."