Discarding

[Maddogmido]

With {trading post} if I discard {scuttling doom engine} to gain life. does the second ability apply ?

[Remillo]

Dying specifically means going from the Battlefield to the Graveyard.  Discarding it from your hand to the graveyard (with the "{T}, Discard a Card: ...") doesn't cause it to die, since it wasn't on the battlefield.  Getting hit with a kill spell or sacrificing it (with two other abilities of Post, for instance) WILL trigger it, since it's going from the battlefield to the graveyard.

[Maddogmido]

Cool thanks