The great thing about Spam Block Service is that you don’t need to worry about how it works as we deal with the whole process for you. However, if you want to learn more about the server spam filter process you can find out everything you need to know here.

What the server spam filter scans for

When our system receives an email it will pass through the following filters to decipher whether the message is spam or a genuine email...

Firstly, the server spam filter will check whether the sender’s email address or domain name features on the email blacklist or whitelist...

  • A blacklist is a list of email addresses and domain names which Spam Block Service will always block. It’s not just known spammers who can be added to the blacklist, as you maintain the list you can add any email addresses or domains you don’t want to receive emails from.
  • A whitelist is a list of email addresses and domain names which Spam Block Service will allow through the filtering process. As with the blacklist, you can maintain the whitelist and add addresses and domains of your choice to ensure you always receive emails from these senders. All emails will be scanned for viruses before they enter your inbox, even if the sender is on the whitelist.

If the email sender doesn’t feature on either the blacklist or the whitelist the email will then go through the greylisting process. Greylisting blocks the first delivery attempt and asks the sending server to send the email again. As most spam sources do not try to resend emails, greylisting prevents these spam emails from entering your inbox.

If the sending server does resend the email then the server spam filter will scan the email for signs of spam throughout the email content and any attachments by performing...

  • Header analysis
  • Body of the message analysis
  • Attachment analysis
  • Attachment virus scan

The server spam filter will then determine whether the email poses a threat to your email system or PC by completing a threat analysis.

After the message has gone through the above process it is either tagged as spam or as a genuine email (also known as ham). Genuine emails are then forwarded onto your own mail server and from there sent to your inbox. As the filtering process is so thorough there will be a slight delay on the email reaching your inbox due to the greylisting process. The length of the delay depends on how often the email server is set to resend – 10 minutes is the maximum time you would ever have to wait for an email.

Accessing quarantined emails

We quarantine all emails for 28 days and you can easily access these via the client portal and release any emails you choose to your inbox to view them. Genuine emails are also stored in this area for 28 days which means the service automatically backs up your emails should you accidently delete a genuine email from your inbox. You can also generate reports using the client area to show how much spam and how many viruses have been recorded as well many other useful reports. If you want to customise your service you can add whitelist and blacklist addresses to your own account for further spam prevention. Whitelisted emails will bypass all spam detection processes including greylisting but they will still be scanned for viruses to ensure your systems are protected.

How the service is set up

Setting up Spam Block Service is simple as the only thing you will need to do is change your MX records in the DNS settings of the domain you would like us to scan the emails for. If the domain you choose is hosted with us we can do this for you. If the domain is hosted elsewhere then we can give you the settings for the change or if you provide us with the login details we can make the changes for you. The service works on standard SMTP email servers such as MS Exchange, Lotus Notes and all Linux based mail servers.
If you would like to find out more about how Spam Block Service works then please contact us.