Email problems with ssl

I have a problem with the email, When I try to download mail from the mailbox will not let me
I look in the log an error and gives me license not solve, please HELP

here is my log

[12:48:22:721]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: portid : 4|

[12:48:22:877]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: protocol : pop3s|

[12:48:22:908]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: tlsenabled : false|

[12:48:22:924]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: host : 172.20.0.15|

[12:48:22:924]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: username : ricardo.rey|

[12:48:24:549]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: mailbox : INBOX|

[12:48:24:549]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: protocol : pop3s|

[12:48:24:549]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: port : 995|

[12:48:24:549]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: tls : false|

[12:48:24:549]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: Obtained mail store from session.|

[12:48:24:658]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: Before closing folder in closeResources|

[12:48:24:658]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: before closing store|

[12:48:24:658]|[06-19-2009]|[com.adventnet.servicedesk.common.MailUtilities]|[INFO]|[26]|: Exception when connecting to store.|

[12:48:24:658]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: javax.mail.MessagingException: Connect failed;

nested exception is:

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target|

[12:48:24:658]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at com.sun.mail.pop3.POP3Store.protocolConnect(POP3Store.java:148)|

[12:48:24:658]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at javax.mail.Service.connect(Service.java:275)|

[12:48:24:658]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at com.adventnet.servicedesk.common.MailUtilities.tryFolderConnection(MailUtilities.java:175)|

[12:48:24:674]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at com.adventnet.servicedesk.setup.action.EMailDefAction.checkConnection(EMailDefAction.java:899)|

[12:48:24:674]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at com.adventnet.servicedesk.setup.action.EMailDefAction.execute(EMailDefAction.java:170)|

[12:48:24:674]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)|

[12:48:24:674]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)|

[12:48:24:674]|[06-19-2009]|[SYSOUT]|[INFO]|[26]|: at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)