Our servers have two primary method of spam control.
One of these forms is RBLs (Real time Block Lists), and SpamAssassin.
RBLs essentially function by performing a DNS query on the IP of a mail server trying to deliver/relay mail through the local server to a DNSBL (Domain Name Server Block List), which contains a list of all IPs known to be sending spam, or known to be an ISP's Dynamic IP range.
This will help reduce known spammers for sending email to our servers, as well as possible trojaned PCs (since ISPs provide their customers with an outgoing SMTP server, no dynamic IP should directly connect to our mail server, unless they are our client.
In which case, our mail server setup will still accept your mail as long as you are using SMTP-AUTH, or you are logging into your POP3 account before connecting to the SMTP server for your hosting account).
SpamAssassin is not enabled by default, and each user needs to turn on themselves if they wish to receieve the spam filtering. To do so, you do the following:
1) Login to your cpanel account
2) Click on Mail.
3) Click on SpamAssassin.
4) Click on Enable SpamAssassin
5) Cliick on Configure SpamAssassin to modify any system defaults, or provide custom settings (optional)
If you already have SA enabled, then we would recommend that you lower your score setting so SA becomes stricter on what is classifies as spam or ham (legitimate mail).