Netgear STM300 STM 150-300-600 Reference Manual (PDF) - Page 97

ProSecure Web/Email Security Threat Management (STM) Appliance Table 29. Email Filter Settings (Continued) Setting Description (or Subfield and Description) Filter by File Type File Extension By default, the File Extension field lists the most common file extensions that are detected. You can manually add or delete extensions. Use commas to separate different extensions. You can enter a maximum of 40 file extensions; the maximum total length of this field, excluding the delimiter commas, is 160 characters. You can also use the drop-down list to add predefined file extensions from a specific category to the File Extension field: • None. No file extensions are added to the File Extension field. This is the default setting. • Executables. Executable file extensions (exe, com, dll, so, lib, scr, bat, and cmd) are added to the File Extension field. • Audio/Video. Audio and video file extensions (wav, mp3, avi, rm, rmvb, wma, wmv, mpg, mp4, and aac) are added to the File Extension field. • Compressed Files. Compressed file extensions (zip, rar, gz, tar, and bz2) added to the File Extension field. Action SMTP POP3 IMAP From the drop-down list, specify an action when an email attachment with a file extension that is defined in the File Extension field is detected. The drop-down list selections and defaults are the same as the ones for the Filter by Password-Protected Attachments (ZIP, RAR, etc.) section earlier in this table. Filter by File Name File Name Enter the file names that are detected. For example, to block the Netsky worm (which normally arrives as netsky.exe), enter netsky.exe. You can enter a maximum of 20 file names. Use commas to separate multiple file names. The maximum total length of this field is 400 characters, excluding the delimiter commas. Action SMTP POP3 IMAP From the drop-down list, specify an action when an email attachment with a name that is defined in the File Name field is detected. The drop-down list selections and defaults are the same as the ones for the Filter by Password-Protected Attachments (ZIP, RAR, etc.) section earlier in this table. 3. Click Apply to save your settings. Protecting Against Email Spam The STM integrates multiple antispam technologies to provide comprehensive protection against unwanted email. You can enable all or a combination of these antispam technologies. The STM implements these spam prevention technologies in the following order: 1. Whitelist. Emails from the specified sources or to the specified recipients are not considered spam and are accepted. 2. Blacklist. Emails from the specified sources are considered spam and are blocked. 3. Real-time blacklist. Emails from known spam sources that are collected by blacklist providers are blocked. 4. Distributed spam analysis. Emails that are detected as spam by the NETGEAR Spam Classification Center are either tagged, blocked, or quarantined. Chapter 4. Content Filtering and Optimizing Scans | 97