Why does changing the file expiration date not affect my uploaded files?

This mechanism is by design, with the main purpose of avoiding any potential data loss for the users who already have uploaded files.

The logic behind the mechanism is as follows: once configured, the expiration date gets applied to any new files that are uploaded to MFT. This is a specific metadata that gets written to each file once it reaches the MFT permanent storage (after being processed and allowed).

Once this metadata is written, it will no longer be possible for it to be altered, because otherwise there would be a high risk of changing the global setting to a value that may cause existing files to automatically be considered expired. If this were to happen, all these files would be deleted with no control over this process. The only possibility is to allow the file to expire then restore it from the Recycle Bin, which will then set a new expiration date based on the configuration.

MFT-to-MFT use case

Beginning with version 3.9.2 of MFT, we have also introduced an additional mechanism to control the expiry date in scenarios where the MFT-to-MFT functionality is used. You can specify an override of the expiry date once the files reach the destination MFT. This can be done on the destination MFT, from the configuration of the API key used to connect the source MFT to the destination MFT.