MailScan stops Spamming and Phishing using a combination of technologies like Non Intrusive Learning Patterns (NILP), Greylisting, Real-time Black List (RBL), SURBL, General Header Tests, MX/A DNS Record Verification, Reverse DNS, X-SPAM Rules Check and more.
RBL is a DNS Server that lists IP Addresses of known Spam sending machines. If the contacting IP is found to be in one of the blacklisted categories, the connection is terminated.
Unlike normal RBLs, SURBL Check works by scanning for the presence of names or URLs of Spam websites in the message body.
MailScan checks the validity of all the headers in the mail and if any of the headers are found to be invalid, the mail will be considered as Spam.
The domain part of the email address in the "MAIL FROM" SMTP command is checked to see if it has a DNS MX (Mail Server) and/or A (IP) record as it is typical of spammers to use non-existent domains in their emails.
A reverse DNS check is performed to see if the connecting IP resolves to a valid domain name before accepting or rejecting the email.
X-Spam Rules are Rules that describe certain characteristics of a mail and they are matched against the mail header, body and attachment to generate a score for each mail. If the score crosses a threshold value, then the mail is considered a Spam.
Sender Policy Framework is a world standard that helps to prevent forgery of sender address and is a powerful mechanism to stop Phishing mails.
The system updates the Bayesian Spam Database with probable phrases and words.
To evade 'word' and 'Phrases' based Spam Control and Content Scanning software solutions, many spammers today are increasingly resorting to the use of images in their mails. The text written inside an image is not scanned by most security solutions and hence not caught by Spam blockers. MailScan uses powerful technologies to filter out image spam.
When a local user sends a mail to an email address, the system automatically adds that ID to the Spam Whitelist.