Symantec™ Security Gateways Reference Guide - Sawmill

126 Preventing attacksAnti-spam measuresYou can use several security gateway features to limit types of email permitted into your organization.These features include:■■■■■■Checking whether or not the email comes from a server known to facilitate spam by making use of oneof the several free open relay lists.Restricting inbound email to only mail destined for the organization by specifying a recipient domain.Using hard or soft recipient limits to control the number of emails received and limit bulk emailings.Filtering for patterns in mail headers to block messages with commonly used spam subject lines.Making use of DNS lookups on sending mail servers to confirm that they are correctly identified.Sending all email through the SMTP proxy with virus scanning enabled for full application inspection,as well as virus checking.You can find configuration information for all anti-spam options in your product’s administrator’s guide.