Scrying Hard or Hardly Scrying (Alliance)

This NPC can be quite tricky to locate if you try to find it from Shadowmoon Valley (if not impossible), therefore I recommend running here from the flightpoint Akeeta's Hovel (Coordinates: 65.6, 18.72) in Spires of Arak. From there, follow the south east road and it should lead you to Urna on top of the hill.

As pointed out in the comments: The road loops around, don't go into the cave!

Took me a bit to find the quest item ([item=118570]), which is required to complete the quest Scrying Hard or Hardly Scrying [H]/ Scrying Hard or Hardly Scrying [A]. This quest is obtained on getting to Personal Wingman status with [follower=218], a Bodyguard Follower that can be assigned to your Barracks.

Completing this quest grants the ability [spell=174927], to access your mailbox in the field!

Below are instructions on locating the quest NPC. Note that there are a lot of mobs in the way, and when you finally reach [npc=87639], you may have an entourage of mobs that need to be killed, unless you have some threat clearing ability.

1. 
   
2. Fly to Akeeta's Hovel in Spires of Arakk.
3. 
   
4. Take the path southeast towards the Pillars of Fate. You will see a series of 4 large purple crystals (called [npc=85099]) defended by [npc=85068]s and [npc=85075]s. Ride past these until you reach a dirt path that splits into 5. Take the leftward path that goes up the ridge - it will essentially curve around till you are headed back towards Akeeta's Hovel, but up the mountain (you should be climbing higher).
5. 
   
6. You will reach another two-way fork immediately - take the dirt path to the right, rather than the cobblestone ahead. If you get to a cave you went the wrong way - backtrack and take the dirt path up the mountain instead.
7. 
   
8. The dirt path will once again wind back and forth till you are higher up the mountain - once you reach the top you should see a Void Portal on the right surrounded by mobs, and on the left a group of mobs channeling into a [npc=85392]. Keep going straight ahead, you will see [npc=87639] at (70,20).
9. 
   

Thanks - this was helpful. Even though you said follow the road, it should be specifically noted that you don't go into the cave; the road sort of wraps around and goes uphill.