Ciao a tutti,

sto sclerando perchè sto cercando di mandare un email tramite log4j.
Come impostazione uso il log4j.xml.
L'applicazione è di tipo standalone, quindi non web.
Lanciando l'applicatione al momento dell'invio dell'email mi presenta tale errore:

codice:
com.sun.mail.smtp.SMTPSendFailedException: 530 5.7.1 Authentication required  at com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:2114) at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:1618) at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1119) at javax.mail.Transport.send0(Transport.java:195) at javax.mail.Transport.send(Transport.java:124) at org.apache.log4j.net.SMTPAppender.sendBuffer(Unknown Source) at org.apache.log4j.net.SMTPAppender.append(Unknown Source) at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:221) at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:57) at org.apache.log4j.Category.callAppenders(Category.java:187) at org.apache.log4j.Category.forcedLog(Category.java:372) at org.apache.log4j.Category.error(Category.java:286) at dao.UtenteDAO.login(UtenteDAO.java:32) at main.Main.main(Main.java:29)
codice:
<appender name="mailAppender" class="org.apache.log4j.net.SMTPAppender">    
     <param name="BufferSize" value="50" />        
     <param name="SMTPHost" value="smtp.mail.yahoo.it" />         
     <param name="SMTPPort" value="25" />        
     <param name="SMTPUsername" value="corso_java@yahoo.it" />         
     <param name="SMTPPassword" value="*******" />         
     <param name="From" value="corso_java@yahoo.it" />         
     <param name="To" value="****************" />         
     <param name="Subject" value="Testing Log4j mail notification" />         
     <layout class="org.apache.log4j.PatternLayout">             
         <param name="ConversionPattern" value="[%d{ISO8601}]%n%n%-5p%n%n%c%n%n%m%n%n" />         
     </layout>         
     <filter class="org.apache.log4j.varia.LevelRangeFilter">             
            <param name="LevelMin" value="error" />             
            <param name="LevelMax" value="error" />         
     </filter>     
</appender>
Mi Sapreste aiutare per favore?

Grazie mille