Buttons: there is no little icon in the Outlook toolbar which allows me to create a ticket from an e-mail.
The Folder HelpDesk add-in might be disabled. You need to enable it and then restart Outlook.
In Outlook, go to Tools and check if the add-in ‘Folder HelpDesk for Outlook Client Tools’ is enabled or disabled. If it is disabled, enabled it.
Outlook 2007: Tools > Options > Trust Center > Add-ins > COM Add-ins
Outlook 2010, 2013 and 2016: File > Options > Add-ins > COM Add-ins