Each mailbox has its own mailbox control structure.Different tasks and interrupts can post a mailbox, but only one task can pend on a certain mailbox.

• 每个邮箱都有自己的邮箱控制结构，可以有不同的任务与中断发送到邮箱，但是只有一个任务可以请求一个特定的邮箱。