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## Security Risk Scan Compressed File Restrictions

The following tables describes the compressed file restrictions available for Security Risk Scans.

#### Security Risk Scan Compressed File Restrictions

Setting | Description
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Decompressed file count exceeds | Type a number to configure a restriction for the number of decompressed files that ScanMail will scan. When the amount of decompressed files within the compressed file exceeds this number, then ScanMail only scans files up to the limit set by this option.
Size of decompressed files exceeds | Type a number that represents the size limit in MB. ScanMail only scans compressed files that are smaller or equal to this size after decompression.
Number of layers of compression exceeds | Type a number from 1-20. ScanMail only scans compressed files that have less than or equal to the specified layers of compression. For example, if you set the limit to 5 layers of compression, then ScanMail will scan the first 5 layers of compressed files, but not scan files compressed to 6 or more layers.
Size of decompressed file is "x" times the size of compressed file | ScanMail only scans compressed files when the ratio of the size of the decompressed file compared to the size of the compressed file is less than or equal to this number. This function prevents ScanMail from scanning a compressed file that might cause a Denial-of-Service (DoS) attack. A Denial-of-Service (DoS) attack happens when a mail server’s resources are overwhelmed by unnecessary tasks. Preventing ScanMail from scanning files that decompress into very large files helps prevent this problem from happening.