When connecting to Cloudsfer you have to select the source and target system you wish to migrate from or to. 

The Amazon S3 option can be used as a source or as a target system.

Using Amazon S3 as a source you will be able to preserve versions of the documents can be migrated and the modified by date. 

In order to connect all you have to do is choose the Amazon S3 connector from the list of systems as shown below.

A pop up screen will appear. 
Make sure you have a S3 key pair. You will need both the access key ID and the secret access key in order to continue.

By clicking on the "List Buckets"button you will be able to choose the needed bucket.

Select the folder you wish to migrate from the hierarchy of the files.    

For example please see the screen shot below: 

Please note these are the following limitations when migrating into Amazon S3:

Cloudsfer does not restrict any sort of file types or size, all limitation are Box limitations.

For any further information please contact Cloudsfer support - support@cloudsfer.com.