Recently, the Net Profit Hosting mail server was subjected to a concentrated and deliberate spam based dos attack. 
It lasted approximately 24 hours, and was delivered in the form of thousands of emails with various sized attachments coming from various ip’s based in the Middle East.  This is not the first attack like this we’ve received, but it’s the first one that taxed our system resources.  Here’s an image showing a skewed view of our recent mail server activity. 

Although there are hundreds of clients using this mail server, the recent attack skews the graph to make our normal usage (5,000+ emails per day) look insignificant.