[Dovecot] IMAP goes down from time to time

[Juan Felipe Estrada]

Good Afternoon

I´m really new at this and i don´t know if i´m posting at the right place.

My problem is that our Dovecot IMAP is stopping from time to time with 
no info in the log, i just realize about this when our support person 
call me saying that the whatsup monitor is showing the IMAP4 process 
down. I can figure about this too by trying to get in our webmail Horde 
and i cannot login.

Here i post my Dovecot -n command i´ll appreciate any help.

/# 1.0.7: /etc/dovecot.conf
protocols: imap pop3 imaps pop3s
ssl_cert_file: /etc/httpd/conf/ssl.crt/unimail.uninorte.edu.co.crt
ssl_key_file: /etc/httpd/conf/ssl.key/unimail.uninorte.edu.co.key
ssl_cipher_list: ALL:!LOW:!SSLv2
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
mail_location: maildir:/home/vmail/%u/Maildir
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/lib64/dovecot/imap
mail_plugin_dir(imap): /usr/lib64/dovecot/imap
mail_plugin_dir(pop3): /usr/lib64/dovecot/pop3
auth default:
  mechanisms: plain login
  cache_size: 300
  cache_ttl: 600
  worker_max_count: 200
  passdb:
    driver: ldap
    args: /etc/dovecot-ldap.conf
  passdb:
    driver: pam
  userdb:
    driver: static
    args: uid=500 gid=500 home=/home/vmail/%u
  userdb:
    driver: passwd
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
/

Thanks so much

Juan Felipe Estrada
Universidad del Norte
Barranquilla Colombia