Comment : while accessing the account via explorer webmail(SquirrelMail version 1.4.3a) 
http://10.5.1.11/webmail/src/redirect.php 
I get the following message  
 
ERROR  
Unknown user or password incorrect.  
Go to the login page  
 
I am running redhat 9 
imap is runnig  
[root@mail courier-imap-3.0.8]# ps -aux | grep imap 
vpopmail  8893  0.0  0.0  1364  408 ?        S    17:49   0:00 /usr/local/courier-imap/sbin/courierlogger imapd 
vpopmail  8907  0.0  0.0  1348  268 ?        S    17:49   0:00 /usr/local/courier-imap/sbin/courierlogger imapd-ssl 
root      8917  0.0  0.0  1476  516 ?        S    17:49   0:00 /usr/local/courier-imap/libexec/couriertcpd -address=0 -stderrlogger=/usr/local/courier-imap/sbin/courierlogger -stderrloggername=pop3d-ssl -maxprocs=40 -maxperip=4 -pid=/var/run/pop3d-ssl.pid -nodnslookup -noidentlookup 995 /usr/local/courier-imap/bin/cour 
root      8920  0.0  0.0  1352  272 ?        S    17:49   0:00 /usr/local/courier-imap/sbin/courierlogger pop3d-ssl 
root      8986  0.0  0.0  1360  420 ?        S    17:56   0:00 /usr/local/courier-imap/sbin/courierlogger -pid=/usr/local/courier-imap/var/authdaemon/pid -start /usr/local/courier-imap/libexec/authlib/authdaemond.ldap 
root      8987  0.0  0.1  4300 1152 ?        S    17:56   0:00 /usr/local/courier-imap/libexec/authlib/authdaemond.ldap 
root      9033  0.0  0.0  3752  560 pts/1    S    18:22   0:00 grep imap 
[root@mail courier-imap-3.0.8]#  
 
in the mail log i found this 
Jul  2 17:56:32 mail authdaemond.ldap: restarting authdaemond children 
Jul  2 17:56:32 mail authdaemond.ldap: modules="authcustom authcram authuserdb authvchkpw authldap authpam", daemons=5 
Jul  2 17:56:34 mail authdaemond.ldap: modules="authcustom authcram authuserdb authvchkpw authldap authpam", daemons=5 
Jul  2 17:57:13 mail imapd: Connection, ip=[::ffff:10.5.1.11] 
Jul  2 17:57:18 mail imapd: LOGIN FAILED, ip=[::ffff:10.5.1.11] 
Jul  2 17:57:18 mail imapd: DISCONNECTED, ip=[::ffff:10.5.1.11], time=5 
Jul  2 17:57:35 mail imapd: Connection, ip=[::ffff:10.5.1.11] 
Jul  2 17:57:40 mail imapd: LOGIN FAILED, ip=[::ffff:10.5.1.11] 
Jul  2 17:57:40 mail imapd: DISCONNECTED, ip=[::ffff:10.5.1.11], time=5 
Jul  2 18:04:55 mail imapd: Connection, ip=[::ffff:10.5.1.11] 
Jul  2 18:05:00 mail imapd: LOGIN FAILED, ip=[::ffff:10.5.1.11] 
Jul  2 18:05:00 mail imapd: DISCONNECTED, ip=[::ffff:10.5.1.11], time=5 
Jul  2 18:05:12 mail imapd: Connection, ip=[::ffff:10.5.1.11] 
Jul  2 18:05:17 mail imapd: LOGIN FAILED, ip=[::ffff:10.5.1.11] 
Jul  2 18:05:17 mail imapd: DISCONNECTED, ip=[::ffff:10.5.1.11], time=5 
Jul  2 18:10:31 mail imapd: Connection, ip=[::ffff:10.5.1.11] 
Jul  2 18:10:36 mail imapd: LOGIN FAILED, ip=[::ffff:10.5.1.11] 
Jul  2 18:10:36 mail imapd: DISCONNECTED, ip=[::ffff:10.5.1.11], time=5 
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