We employ two kinds of anti-spam technology to protect our customers against spam:
- At the server level, we use a DNS Blacklist (DNSBL) to reject emails being sent from servers known to be sending out spam
- On the user account level, we offer an anti-spam solution to scan and filter emails before they arrive into our customer's email inboxes
What is a DNS Blacklist and how does it work?
A DNS Blacklist (DNSBL) is a list comprised of the IP addresses of email servers which are known for sending out spam. Email service providers, such as ourselves, query these lists to identify servers known to be sending out spam. Once a server is detected on these lists, we reject all emails sent from those servers until those servers IP address are removed from the lists. This allows us to reject the majority of spam prior to the processor intensive task of scanning individual emails against a database of spam tests.
If an email is sent from a server whose IP address is listed on one of the DNSBLs that we subscribe to, our mail server will reject the email immediately. If a user discovers that their mail server has been listed on a DNSBL, they should inform their email hosting provider immediately. It is the responsibility of the email hosting provider who has been placed on the DNSBL to investigate the reason they've been placed on the list, resolve the issue, then take appropriate action to get their server removed from the list.
We are not able to have IP addresses owned by third parties removed from the list on the behalf of customers of other email hosting providers.
How does our anti-spam solution work?
After passing through our DNSBL check, emails are scanned by our anti-spam filtering system before arriving into customers inboxes or being quarantined. Our anti-spam system allows users to:
- Modify how strict they want the anti-spam checks to be
- Block specific file extensions in email attachments
- Restrict the size of accepted emails
- Manage domain level whitelists and blacklists
- Monitor the email delivery queue
- Mark emails as spam
- View a report of all spam messages received
- Search email logs
Our anti-spam solution uses a centralised quarantine database, allowing us to share data relating to known spammers and spam emails with other email hosting providers who employ the same anti-spam solution. This helps protect our users inboxes better than spam solutions which are simply installed and run in an isolated environment.