What is this message from root: E-mail message limit for ip.addre.ss has been reached

[casey]

Email message limit for xx.xx.xx.xx has been reached

I get these every once in a while, but when I look at my statistics, no SPAM has apparently been sent. No one is listed on the relayers, either, but the IP has been blocked from accessing the server. That's all fine and dandy, but what does it mean?

Does that actually mean, "Someone tried to use your server as an open relay, so they have been rejected" ?

cPanel.net Support Ticket Number:

[mickeymouse]

Dear casey,

Some ISPs do limit the amount of mail they receive from a server. On a shared server all email is sent from the main server IP. So this might sometimes happen. This does not cause/indicate any harm.

Regards,

[casey]

I had forgotten about this message. Thanks. I contacted my datacenter, because most of the IPs were from there. They said it is people trying to find out if they can send spam from my server. Once they try that the IP gets blocked. No spam was sent from my server. Those messages tell you that psad is doing its job.

The messages aren't coming from ISPs, they're coming from root.