Notes on Content Disarm and Reconstruction (CDR)

PDF conversion, also called Content Disarm and Reconstruction (CDR), converts Microsoft Word and Microsoft Excel documents and PDF documents into PDF files, removing any active content that may be present. The PDF file can then be opened without hesitation, and the original file can either be left on the email or removed.

CDR is a feature in NoSpamProxy Protection and, in conjunction with NoSpamProxy Large Files, offers an optimal way to defuse unsafe documents and retain the original files.

CDR is configured in the Content filter actions and then applied to the corresponding emails via the content filters. A training video on content filters can be found under Videos (German only). See Creating content filter actions.

This conversion process is very complex and not every document can be converted. For this purpose we have built in a protection mechanism so that the unsafe attachments are not delivered, even if the conversion fails.

• If only Protection, but no Large Files, is licensed, the email for which the conversion did not work is first parked under "Monitoring > Emails on hold" and the configured administrator is informed. This person then has the task of checking the email and can then either forward it via Outlook by downloading it as an EML file or temporarily deactivate/change the content filter for this email and thus force delivery again.
• If Protection and Large Files are licensed, the original file is loaded onto the Web Portal if the conversion fails - if desired also if the conversion is successful - but is then locked there so that it must also be released by the administrator - in contrast to the settings for successful conversion. The email itself is delivered to the recipient, with the appropriate information for downloading, but without the converted PDF file, as this was not possible.

NOTE: This protective mechanism cannot be changed or influenced.

NOTE: As the conversion component is provided by a third party, we have very limited influence over it. If the conversion cannot be carried out to your satisfaction, send us the file to be converted, if possible. Make sure that the file does not contain any personal data. We then make this file available to the third-party provider for analysis. We would like to point out that feedback from our side is not possible, as the adjustment process can be very lengthy.