Index: haiku/src/apps/mail/Header.cpp
===================================================================
--- haiku/src/apps/mail/Header.cpp	(revision 41262)
+++ haiku/src/apps/mail/Header.cpp	(working copy)
@@ -390,6 +390,19 @@
 		}
 		y += controlHeight;
 	}
+	
+	if (fIncoming) {
+		--y;
+		r.Set(SEPARATOR_MARGIN, y,
+			windowRect.Width() - SEPARATOR_MARGIN, y + menuFieldHeight);
+		y += controlHeight;
+		fCc = new TTextControl(r, B_TRANSLATE("Cc:"),
+			NULL, fIncoming, false, B_FOLLOW_LEFT_RIGHT);
+		fCc->SetEnabled(false);
+		fCc->SetDivider(x - 12 - SEPARATOR_MARGIN);
+		fCc->SetAlignment(B_ALIGN_RIGHT, B_ALIGN_LEFT);
+		AddChild(fCc);
+	}
 
 	--y;
 	r.Set(SEPARATOR_MARGIN, y,
@@ -708,8 +721,10 @@
 		if (fBcc != NULL)
 			fBcc->SetEnabled(false);
 
-		if (fCc != NULL)
+		if (fCc != NULL) {
 			fCc->SetEnabled(false);
+			fCc->SetText(mail->CC());
+		}
 
 		if (fAccount != NULL)
 			fAccount->SetEnabled(false);
@@ -719,6 +734,29 @@
 
 		fSubject->SetEnabled(false);
 		fTo->SetEnabled(false);
+		
+		// show/hide CC field
+		bool haveText = false;
+		if (mail->CC() != NULL && strlen(mail->CC()) > 0) {
+			haveText = true;
+		}
+		bool isHidden = fCc->IsHidden(this);	// hidden relative to parent
+		if (haveText && isHidden) {
+			float diff = fAccountTo->Frame().top - fTo->Frame().top;
+			fSubject->MoveBy(0, diff);
+			fDate->MoveBy(0, diff);
+			fDateLabel->MoveBy(0, diff);
+			fCc->Show();
+			this->ResizeBy(0, diff);
+		}
+		else if (!haveText && !isHidden) {
+			float diff = fAccountTo->Frame().top - fTo->Frame().top;
+			fSubject->MoveBy(0, - diff);
+			fDate->MoveBy(0, - diff);
+			fDateLabel->MoveBy(0, - diff);
+			fCc->Hide();
+			this->ResizeBy(0, - diff);
+		}
 	}
 
 	//	Set Subject: & From: fields