The Anti Spam modules does not only block spam from entering to your network but it also have the ability to customize based on requirement to filter out email that sent from certain domain and most likely from those free webmail domain.
In this write up will show you on how to block email from Hotmail, Gmail or Yahoo domain being rejected by Cyberoam at the gateway level before reaching internal mail server. Please take note that this only works when you hosted your own mail server.
1) First login into Cyberoam web interface and point to “Anti Spam” -> “Spam Policy” -> “Create Custom Policy”, the following screen will appear
Provide the name for this rule, press “create” to continue on the policy creation
2) After done the previous step, click on the “Add” button as below
3) Here you can add the domain that you need to block and select the “SMTP Action” whether you need it to be dropped or reject.
Click on “Create” button to add into the list and you have to add for each of the domain that you need to be blocked as below
The custom policy have been successfully create and now proceeding to the Spam Rule that Cyberoam will process anti spam according to the spam rule. To create the spam rule, follow the following steps:-
1) Click on “Anti Spam” -> “Spam Rules”
2) Click on “Create” to create new spam rule
On the “Action Item” select “Recipient Email Address” where you type in the customer domain name into “Recipient email Address” and on the “Policy Name” select the policy that you have created earlier then press “Add” button.
You will be getting something like the above screenshot and these are the steps for blocking external email.
Note: Make sure to enable SMTP scanning on the firewall policy for incoming traffic.
This guide is solely created by me and if there is any mistake or does not works, please do inform me and i will do the correction.