使用springboot+vue弄的一个发送邮件的功能但是非常不稳定，有时候能发送成功有时候报错，动态配置的发件人信息，现在还了一个发件人就报这样的错误了，求帮忙解决，非常感谢!
![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/446724155886180.png "#l
- 请求地址'/mail/mail/sendSimpleMessage',发生未知异常.
cn.hutol.extra.mail.MailException: MessagingException: Can't send command to SMTP host
at cn.hutool.extra.mail.Mail.send(Mail.java:398)
at com.ruoyi.common.utils.email.MailUtils.send(MailUtils.java:444)
at com.ruoyi.common.utils.email.MailUtils.send(MailUtils.java:171)
at com.ruoyi.common.utils.email.MailUtils.send(MailUtils.java:154)
at com.ruoyi.common.utils.email.MailUtils.send(MailUtils.java:95)
at com.ruoyi.common.utils.email.MailUtils.sendText(MailUtils.java:65)
at com.ruoyi.web.controller.mail.MailinitializationController.sendSimpleMessage(MailinitializationController.java:38)
at com.ruoyi.web.controller.mail.MailinitializationController$$FastClassBySpringCGLIB$$3adc6cb1.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
at org.springframework.validation.beanvalidation.MethodValidationInterceptor.invoke(MethodValidationInterceptor.java:123)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708)
at com.ruoyi.web.controller.mail.MailinitializationController$$EnhancerBySpringCGLIB$$577daa8d.sendSimpleMessage(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1071)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:964)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:497)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:584)
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:91)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:67)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at com.ruoyi.common.filter.RepeatableFilter.doFilter(RepeatableFilter.java:30)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:67)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:67)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:67)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:96)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:67)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:67)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:117)
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.SendErrorPageHandler.handleRequest(SendErrorPageHandler.java:52)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:275)
at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:79)
at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:134)
at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:131)
at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:255)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:79)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:100)
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:393)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:852)
at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:2019)
at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1558)
at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1449)
at org.xnio.XnioWorker$WorkerThreadFactory$1$1.run(XnioWorker.java:1282)
at java.lang.Thread.run(Thread.java:750)
Caused by: javax.mail.MessagingException: Can't send command to SMTP host
at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:2431)
at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:2418)
at com.sun.mail.smtp.SMTPTransport.close(SMTPTransport.java:1394)
at javax.mail.Transport.send0(Transport.java:233)
at javax.mail.Transport.send(Transport.java:100)
at cn.hutool.extra.mail.Mail.doSend(Mail.java:412)
at cn.hutool.extra.mail.Mail.send(Mail.java:390)
... 91 common frames omitted
Caused by: java.net.SocketException: Connection or outbound has closed
at sun.security.ssl.SSLSocketImpl$AppOutputStream.write(SSLSocketImpl.java:1144)
at com.sun.mail.util.TraceOutputStream.write(TraceOutputStream.java:116)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:2429)
... 97 common frames omitted
