Mail routing

Hi,

I have hub and spoke server architechure. The mail routing happens using connection document as they all are in different NNN. Mail routing happens very good upto three days and on the fourth day it starts the pending the mails. When excute the tell router show command it shows the remote server is busy. So tried to disconnect the old session by applying the command tell router quit. After 3 min again i load the router but still the problem is same. But the interesting thing is that after total server restart it works fine and all pending mails will start routing. so if anyone face the same problem and how they reslove the same please let me know.

Waiting for + response.

Thanks in advance