3161076 - Workflow email notification image is not displayed

When sending an email notification, I can use an 'email banner'/picture.
I do this through: 

My picture is visible when previewing the email message. (attachment preview email)
However, when receiving the mail, this banner/picture is not shown. (attachment email picture not showing)

What is the reason why this picture is not showing?

Please check if the image is available without being logged in to Sharepoint. Usually this problem stems from the fact that the image is not publicly available.

Please also read the information provided in the user guide.

KBA , BPI-SIG-PG-EDT , Process Governance Editor , How To

SAP Signavio Process Governance all versions ; Workflow Accelerator by Signavio all versions