[Dovecot] Slow IMAP Auth

[Jeff Duncan]

Hello,

I am experiencing IMAP authentication delays when a client first authenticates, or after the last auth timeout.  There are only a handful of clients - less than 5 - using the server.  I am using a mysql database and I have verified the PAM auth is commented out.  Other than that I can't figure out what might be causing the slow authentication.  The first time a client authenticates with SSL/CRAMD5 it takes almost 20 seconds.  Does anyone have any suggestions?  My config and version is below:

mail:~# dovecot --version
1.1.11

mail:/usr/share/gallery2# dovecot -n
# 1.1.11: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.26-2-686 i686 Debian 5.0.3 ext3
log_timestamp: %Y-%m-%d %H:%M:%S 
protocols: imap imaps pop3 pop3s
login_dir: /var/run/dovecot/login
login_executable(default): /usr/lib/dovecot/imap-login
login_executable(imap): /usr/lib/dovecot/imap-login
login_executable(pop3): /usr/lib/dovecot/pop3-login
mail_max_userip_connections(default): 20
mail_max_userip_connections(imap): 20
mail_max_userip_connections(pop3): 10
first_valid_uid: 6060
mail_privileged_group: mail
mail_location: maildir:/var/vmail/%d/%n
mail_executable(default): /usr/lib/dovecot/imap
mail_executable(imap): /usr/lib/dovecot/imap
mail_executable(pop3): /usr/lib/dovecot/pop3
mail_plugins(default): autocreate quota imap_quota
mail_plugins(imap): autocreate quota imap_quota
mail_plugins(pop3): quota
mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3
auth default:
 mechanisms: plain login cram-md5
 passdb:
   driver: sql
   args: /etc/dovecot/dovecot-sql.conf
 passdb:
   driver: sql