Well, I checked the base v7 mail templates and don't see it there either, and someone actually asked about it. Admittedly I never used it, but it is gone.
Code was this:
FIELD EnterSendTo:= EnterSendTo ;
FIELD EnterCopyTo:= EnterCopyTo ;
FIELD EnterBlindCopyTo:= EnterBlindCopyTo ;
temp1 := @Sort(EnterSendTo);
temp2 := @Sort(EnterCopyTo);
temp3 := @Sort(EnterBlindCopyTo);
@SetField("EnterSendTo";temp1);
@SetField("EnterCopyTo";temp2);
@SetField("EnterBlindCopyTo";temp3)
Right above the "To" to the left of the address field.