It seems you cannot send an email to an external contact without this contact being known in the ServiceDesk portal from the incident process view actions.

This functionality is pretty much used by all my Helpdesk/ServiceDesk customers.

Please embed this functionality out-of-the-box again in ServiceDesk 7.5.x

Many thanks!

Orig. forum question: https://www-secure.symantec.com/connect/forums/servicedesk-75-send-email-external-contact-within-incident

kr, dawi_x