The following settings are available. In SpamFilter Enterprise, each email domain can be configured independently with different settings. The "ALL DOMAINS" is a reserved entry that contains default filtering values to all domains. Each domain can be given customized filter settings by clearing the "Use Defaults" checkbox.
 Figure 2
• | Min MAPS matches needed to reject msgs - Sometimes MAPS blacklists can be too strict and list legitimate domains in their blacklists. You can reduce the number of false positive by requiring that more than one single blacklist match is found before rejecting a connection. |
• | Max number of spaces in subject line - Many spam messages contain a large number of spaces and tabs, and SpamFilter can reject emails based on this setting. Enter a “0” to disable this filter. |
• | Image filter threshold – SpamFilter scans inside images embedded in emails to detect spam signatures. Use this setting to adjusts the threshold of the image filter. The higher the threshold, the more aggressive the filter. Enter a “0” to disable the image filter. |
• | Reject if no reverse DNS - SpamFilter can be configured to reject emails if the remote server does not have a valid reverse DNS PTR entry. |
• | Reject if sender domain has invalid MX record – SpamFilter can check to see if the sender’s email domain has a valid MX record. If the MX record is not present in the DNS, the email will be rejected. The email domain in this case is what follows the “@” sign in the sender’s email address. For example, is the sender is user@sub.domain.com, the domain that will be tested for the presence of an MX record is sub.domain.com. |
• | Reject if Empty "Mail From" - If this option is checked SpamFilter will reject all emails with an empty "Mail From" field. Please note that this setting will delete legitimate email, as in email receipt notifications and some error emails. |
• | Reject if "Mail From" = "Mail To" - Reject all emails where the sender's email is the same as the recipient's email. Note that this causes problems with users who send emails to themselves using EBay's web interface for example. |
• | Reject if "From Domain" = "To Domain" - SpamFilter can reject all email where the sender's domain is the same as the recipient's domain. Usually your users will not go thru SpamFilter when sending emails to themselves, Spammers often use this technique |
• | Allow % in address - SpamFilter can then optionally check to see if the recipient address has a % sign in it. Many SMTP servers are susceptible to being tricked into relaying mail with this. Ex. if you are isp.com, then a spammer could try to use joe%yahoo.com@isp.com to relay mail to joe@yahoo.com if your server is vulnerable. |
• | Tag Spam & Deliver - Allows to tag spam by adding the header "X-SF-SPAM:Y" to email classified as spam. The email is then forwarded to the destination SMTP server. This allows administrators to handle spam as they wish on the back-end. |
• | Tag Spam in Subject & Deliver - Allows to tag spam by prefixing the word SPAM: in the subject line of emails classified as spam. The email is then forwarded to the destination SMTP server. This allows administrators to handle spam as they wish on the back-end. |
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