How can a hoster detect spammers among clients?

Question

Fight against spam

Need your advice.

What software is needed to provide hosting?
So far I've settled on:

• CentOS x64
  
• ISPmanager pro
  
• Apache mpm-itk php 5.3
  
• php 5.2 CGI
  
• MySQL 5.1
  
• munin - for monitoring iron problems
  

Interested in your opinion on this list.

And I did not find any information about programs that would catch email spammers among clients and those that use CURL. Or they didn’t even catch it, but at least did some kind of monitoring so that I could respond to abuses and localize a specific user.

Answer 1

enable SMTP authorization for users and analyze mail server logs with the output of the top most active email senders per hour, let's say. As an option - determine the boundary values ​​\u200b\u200band shove it into the monitoring system

Answer 2

It is better to prevent spam than to look for it, because in many cases the user is simply hacked and does not know that spam is being sent from his account.
Spam can be sent in two ways
1) By means of an installed mail server (for example, exim)
2) Directly from php, perl, etc.
To prevent spam you need to
1) To prevent sending, the first option is to set limits for users if you have exim, similar to this one . Of course, you don't need to follow that instruction, just peep how it is implemented there
2) Close all outgoing connections on mail ports using iptables for everyone except the user from which Exim is running

Answer 3

To prevent spam, the best way is:
1) fix this moment in the contract with the client (if you don’t conclude it in writing, then in the offer on the website) ...
2) before starting a new client, talk to him and discuss this moment ..