logout problem

[berengere.pons]

i have found in /var/log/auth.log:
sep 12 15:00:00 Login x.x.x.x to mail.server :110 as user
sep 12 15:00:11 FAILED x.x.x.x to mail.server:110 as user

these two phrases are written in mailbox.php3 and in horde.lib

What can i do please?

PS: see my last mail for more informations
i use pop3

"Ce message vous est envoyé par laposte.net - web : www.laposte.net/  minitel : 3615 LAPOSTENET (0,84 F TTC la minute)/ téléphone : 08 92 68 13 50 (2,21 F TTC la minute)"