The mailing list for listmasters using Sympa

[address@concealed]

I'm using sympa 2.7a on a linux server with mysql. My list has more than 
50,000 subscribers. It's an announcement only list and I am the only person 
authorized to send messages to the members. My problem is that somehow a 
message with the sircam virus in an attached filed has gone into the system 
and is being sent to all the subscribers. I didn't send this message (my 
computer is virus free) and I still don't know what happened. I already 
changed the owner address to avoid more messages being sent, but my urgent 
problem is to stop the messages from sending.

I stopped sendmail as a provisional measure but I don't know if there is a 
way to erase a message from the queue directly from sympa, so that it is not 
sent to the whole list. I tried editing sendmail mqueue but when I restart 
sendmail the messages restart to be sent too.

Please, I'd really appreciate a quick answer. I don't want to send virus 
infected messages to my subscribers.

Thanks, 
Carlos