异常记录

resion下javamail出异常java.lang.SecurityException: Access to default session denied
Caused by: java.lang.SecurityException: Access to default session denied
at javax.mail.Session.getDefaultInstance(Session.java:311)
程序用调度每晚12点自动发送邮件,前一段时间一直正常运行,一天突然报该异常导致不能发信
查找原因
It means some other application, or the app server itself, has already created
the default session using Session.getDefaultInstance and your application,
which has different privileges, is trying to use the default session using
Session.getDefaultInstance. Most likely your application will be much happier
if it just uses its own session instead of the default session.

Use Session.getInstance. See the javadocs for the difference.
理解了下:
当应用或者服务本身应将创建默认session,当他们都试图使用session时,会根据不同的权限来分配,解决办法是使用自己创建的session来代替默认的session
修改代码
mailSession = Session.getDefaultInstance(props, me);// 出异常
mailSession = Session.getInstance(props, me);//
能力有限理解可能存在偏差
注:
  当我重启服务修改调度时间来发送邮件时,没有复现该问题!