The domains are stored in the “~/.spamassassin/user_prefs” config file.
To blacklist a domain just add it to the config file.
blacklist_from *.domain_to_block.com
To whitelist, change blacklist to whitelist
whitelist_from *.incredigeek.com
Save and exit the file.
For some reason the hosts.allow and hosts.deny files don’t seem to work on cPanel. One of the alternative methods to limit ssh logins to specific addresses is to use iptables.
Allow access from specific IP addresses.
Replace 192.168.1.0/24 and 192.168.0.0/24 with your addresses. You can add more addresses using the “,”. Also if your ssh port is not the default port, be sure to change it.
iptables -A INPUT -s 192.168.1.0/24,192.168.0.0/24 -p tcp --dport 22 -j ACCEPT
Reject access from everywhere else
iptables -A INPUT -s 0.0.0.0/0 -p tcp --dport 22 -j REJECT
You can see your rules with
iptables -L --line-numbers
If you need to add another rule after the fact, you’ll need to make sure that it is above the REJECT rule. you can use the “-I” to insert it between rules.
Example: inserts rule as the second rule in the INPUT chain
iptables -I INPUT 2 -s 192.168.42.0/24 -p tcp --dport 22 -j ACCEPT
Add iptable rule
The following rule rejects access to port 22 on all devices except ones on the 192.168.1.0/24 network. Note the “!”. This command can be useful for a WHM/cPanel server to limit ssh access.
iptables -A INPUT ! -s 192.168.1.0/24 -p tcp --dport 22 -j REJECT
List iptable rules with line numbers
iptables -L --line-numbers
Example output
root@localhost [~]# iptables -L --line-numbers Chain INPUT (policy ACCEPT)Chain OUTPUT (policy ACCEPT) num target prot opt source destination 1 REJECT tcp -- !192.168.1.11 anywhere tcp dpt:ssh reject-with icmp-port-unreachable Chain FORWARD (policy ACCEPT) num target prot opt source destination Chain OUTPUT (policy ACCEPT) num target prot opt source destination 1 ACCEPT tcp -- anywhere anywhere multiport dports smtp,urd,submission owner GID match mailman 2 cpanel-dovecot-solr all -- anywhere anywhere Chain cpanel-dovecot-solr (1 references) num target prot opt source destination 1 ACCEPT tcp -- anywhere anywhere multiport sports 8984,7984 owner UID match cpanelsolr
Remove iptable rule
To delete a rule use the -D option with the Chain and the line number. So to delete the first rule in the example output above, we would specify the INPUT chain and the the line number 1
iptables -D INPUT 1