Quote Originariamente inviata da valia Visualizza il messaggio
stampa tutto lo stacktrace e assicurati che l'errore sia quello intanto.
Non ammazzare gli stacktrace e non andare altrove se non sai bene che errore hai e chi lo genera
Andando in debug e analizzando l'eccezione che viene scatenata mi restituisce questo:

codice:
com.sun.mail.smtp.SMTPTransport.issueCommand(SMTPTransport.java:2080), 
com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1910), 
com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:652), 
javax.mail.Service.connect(Service.java:317), 
javax.mail.Service.connect(Service.java:176), 
javax.mail.Service.connect(Service.java:125), 
javax.mail.Transport.send0(Transport.java:194), 
javax.mail.Transport.send(Transport.java:124), 
dipendenteNew.action.ActionEmail.rispondiEmail(ActionEmail.java:219), 
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method), 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57), 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43), 
java.lang.reflect.Method.invoke(Method.java:606), 
com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450), 
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252), 
org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167), 
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265), 
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68), 
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249), 
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249), 
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171), 
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98), 
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246), 
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139),