Mail Queue Problem

It seems that my mail queue increasing very fast with email and the delivery of new mails becomes very slow.

I have emptied the mail queue a couple of times and the queue keep holding mails. The last time i emptied the last was 2 days ago and the list currently has 970 messages.

I tried flushing the list through virtualmin panel through command line but seems not work as well .

I need some some help here pls (?)

Status: 
Closed (fixed)