[Mailman-Users] How to know if all messages were distributed

[Regis]

Hello,

I sent my first mailingfew days ago  to an important number of 
subscribers : about 200 000 (!).

However, i wonder if the distribution has been complete...

Indeed 72 hours after the mailing, i continue to see permanently about 
500 messages in the queue of my messaging server (i have a linux centOS 
VPS with Qmail).
But what is strange is that actually some of those messages were really 
distributed : I am sure because I got return receipt emails for them !

So i am confused on the total distribution of my mailing to all 
subscribers : is there a possibility so see the number of messages 
processed or not yet processed directly from the server (logs...) ?

THANKS A LOT :-)
Regis.