The second company creates and sends {HEAD ~ an email} containing the content to {TAIL ~ customers} of the second company 
to
The second company creates and sends { HEAD ~ an email } containing the content to { TAIL ~ customers } of the second company
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH