When you receive long emails at gmail the C4C Gmail Add-In overlap part of the email text and hide the scrollbar.
Google Chrome ; SAP Hybris Cloud for Customer
This is a known limitation with the add-in.
As a workaround you can open the email in a new window using the shift+f keyboard shortcut.
Gmail; Add-in , KBA , LOD-CRM-GW-GM , Gmail , Problem