E-sign or electronic signature is a feature to enhance accountability in your proofing process. By enabling e-sign you can have every approver sign the artwork electronically at the stage that they are assigned a task.
To enable e-sign, go to settings button on top right of your account. From there scroll down for the e-sign toggle and enable it (Only available for enterprise accounts)
Once you have approved this, when you are running a project, the system would ask the approver to e-sign when approving the artwork.
After an Artwork is approved, if you want to check who all have signed the artwork, you can go to Artwork (top tab) -> Select the artwork -> Click on the artwork (launching the renderer)-> Click e-sign to view all signatures.