与Outlook服务器的春天java邮件smtp连接问题

Question

我正在尝试通过spring java mail API发送邮件，而我的邮件服务器是outlook。

所以我面临以下问题。

有时会与smpt主机建立连接，有时会返回连接超时。

下面我正在粘贴堆栈跟踪。

SMTP host:example.com.mail.protection.outlook.com, port: 25;
  nested exception is:
        java.net.ConnectException: Connection timed out (Connection timed out)
        at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailS                                                                                        enderImpl.java:404)
        at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSen                                                                                        derImpl.java:332)
        at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSen                                                                                        derImpl.java:347)
        at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSen                                                                                        derImpl.java:336)
        at com.condivision.rentongo.service.MailService.sendMail(MailService.jav                                                                                        a:75)
        at com.condivision.rentongo.service.MailService$$FastClassBySpringCGLIB$                                                                                        $1ed18523.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:2                                                                                        04)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterce                                                                                        ptor.intercept(CglibAopProxy.java:649)
        at com.condivision.rentongo.service.MailService$$EnhancerBySpringCGLIB$$                                                                                        5228ed74.sendMail(<generated>)
        at com.condivision.rentongo.service.OrderService.updateOrderAndInventory                                                                                        Status(OrderService.java:726)
        at com.condivision.rentongo.service.OrderService$$FastClassBySpringCGLIB                                                                                        $$a056f002.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:2                                                                                        04)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation                                                                                        .invokeJoinpoint(CglibAopProxy.java:717)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(                                                                                        ReflectiveMethodInvocation.java:157)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.