@Barrygbg1 The Form 709 cannot be e-filed nor can it be mailed to the same address as a federal tax return.
As stated in the Form 709 instructions -
Where To File
File Form 709 at the following address.
Department of the Treasury
Internal Revenue Service Center
Kansas City, MO 64999
If using a PDS, file at this address.
Internal Revenue Service
333 W. Pershing Road
Kansas City, MO 64108
