What is this?

[deskovbg]

http://prntscr.com/m8gbp2

[niko7boi]

That is just a first email you get from auction house everytime you sell an item, you will get a new email with that gold amount after that timer runs out.
So basically in your picture it says your Silk Cloth is sold for 4g 50s 25c and you're going to get them dont worry. :)
It means the same for all items once the item is sold it takes 1 hour to receive the gold from it.

[Kajmak4ee]

Is there an add-on to delete only this type of mail? It's pretty much spam at this point, as sales are finalized when it's bought out.
Or why don't we get the gold instantly?