Revert "Revert "测试下是否同时发两封""

This reverts commit 29663e0495a1deaa8bd8cfa752f98544ea1832f6.
Revert "Revert "之前测试代码错了，修改下""

This reverts commit 1b1fcce56d7789a439f7474216cce2d55eca7c2b.
换个邮箱测试