[Mailman-Users] Sevier Issue with mails, are these compromised?

[Amit Bhatt]

Hello all,

I have recently shifted my site and mailing list on Hostgator server here in India.
Today, I've got an E-Mail from them saying that as per the mail policy, our members can send 500 mails per hour but we are exceeding the number of mails a day!
While the fact is we have around 360 members and we send hardly 50 to 60 messages in entire day of 24:00.
so, I am unable to understand what's wrong with us. Are some of our mails account got hacked and compromised?
Hostgator team has send me the number of messages and Email addresses sent from: 
-------------------------- 
sayeverything-bounces at sayeverything.org: 11,655 
mailman-bounces at sayeverything.org: 4 
sayevery at in6.hostgator.in: 2 
moderator at sayeverything.org: 1 

They also send me some Random recipient addresses. 

Please advise me, what it looks like, problem with some mailman setting at our end? any issue with the technicality of my service provider? or as I suspect, are above mail accounts being misused?

Thanks,

Amit Bhatt