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## How do I calculate the size of a decompressed file?

For compressed files, how can I calculate the "x" value and use it effectively for the option Size of decompressed file is "x" times the size of compressed file?
This function prevents ScanMail from scanning a compressed file that might cause a Denial-of-Service (DoS) attack. A 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.
Example: For the table below, the "x" value is 100.

#### Decompressed File Examples

File Size (not compressed) | File Size (compressed) | Result
--- | --- | ---
500 KB | 10 KB (ratio is 50:1) | Scanned
1000 KB | 10 KB (ratio is 100:1) | Scanned
1001 KB | 10 KB (ratio is 100.1:1) | Not scanned *
2000 KB | 10 KB (ratio is 200:1) | Not scanned *

* ScanMail takes the action you configure for unscannable files.