is my friend yahoo inbox 1) too full? 2)deactivated or 3)closed or 4)something wrong with yahoo system?

Question

when i sent email to my friend, it bounce back and [e-mail] say :

''Unable to deliver message to the following address(es).
Can't open mailbox for [e-mail]. Temporary error
//I'm not going to try again; this message has been in the queue too long ''

What the problem with it? is my friend yahoo inbox 1) too full? 2)deactivated or 3)closed or 4)something wrong with yahoo system? Have you ever seen that in your inbox?

I expect for exact answer to know the exact reason (1,2,3, or 4), Thank you for all of your help

Answer 1

something wrong with the yahoo system

Answer 2

attempt sending a mail to a distinct Yahoo mail handle. If it rather works then, your associates Yahoo mail handle is complete, deactivated or he/she had blocked your handle. besides, your handle does not have any issue reason you may deliver and acquire mail. BYE

Answer 3

2) deactivated