Anti-Spam filters
GFI MailEssentials uses various scanning filters to identify spam:
| Filter | Description | Enabled by Default |
|---|---|---|
| SpamRazer | An anti-spam engine that determines if an email is spam by using email reputation, message fingerprinting and content analysis. | Yes |
| Anti-Phishing | Blocks emails that contain links in the message body pointing to known phishing sites or if they contain typical phishing keywords. | Yes |
| Director Harvesting | Directory harvesting attacks occur when spammers try to guess email addresses by attaching well known usernames to your domain. The majority of the email addresses are non-existent. | Yes (only if GFI MailEssentials is installed in an Active Directory environment) |
| Email Blocklist | The Email Blocklist is a custom database of email addresses and domains from which you never want to receive emails. | Yes |
| IP Blocklist | The IP Blocklist is a custom database of IP addresses from which you never want to receive emails. | No |
| IP DNS Blocklist | IP DNS Blocklist checks the IP address of the sending mail server against a public list of mail servers known to send spam. | Yes |
| URI DNS Blocklist | Stops emails that contain links to domains listed on public Spam URI Blocklists. | Yes |
| Sender Policy Framework | This filter uses SPF records to stop email sent from forged IP addresses by identifying if the sender IP address is authorized. | No |
| Anti-Spoofing | Checks emails received with a sender email address claiming to originate from your own domain against a list of IP addresses by GFI MailEssentials. If the sender IP address is not on the list of own-domain server IP addresses, email is blocked. | No |
| Greylist | The Greylist filter temporarily blocks incoming emails received from unknown senders. Legitimate mail systems typically try to send the email after a few minutes; spammers simply ignore such error messages. | No |
| Language Detection | Determines the language of the email body text and configurable to block certain languages. | No |
| Header Checking | The Header Checking filter analyses the email header to identify spam emails. | No |
| Spam Keyword Checking | This filter enables the identification of Spam based on keywords in the email being received. | No |
| Bayesian analysis | An anti-spam filter that can be trained to accurately determine if an email is spam based on past experience. | No |
| Whitelist | The Whitelist contains lists of criteria that identify legitimate email. Emails that match these criteria are not scanned by anti-spam filters and are always delivered to the recipient. | Yes |
| New Senders | The New Senders filter identifies emails that have been received from senders to whom emails have never been sent before. | No |