It somewhat worked for me. This is what I did.
Had a Relic of Yu'lon that I disenchanted a while ago when I came back from my WoW-break.
Made a ticket asking for it back, the next day my ticket was answered and I got Relic of Yu'lon in my mailbox but they didn't take a Maelstrom Crystal from my bags (oversight from their part? doesn't matter).
So now I had the mail from Blizzard in my mailbox with Relic of Yu'lon (BoE) but I read the comments here and most of them said it will become BoP if you take it out.
So I thought let's try something new, bam I deleted the mail WITH the Relic of Yu'lon still attached. Made a ticket instantly afterwards saying I feel so embarrassed that I just deleted the mail without taking out the item.
The response I got was something along the lines of "the item restoration limit is 1 per month, but for this case an exception can be made considering how the item was lost". And I got a new mail with a new Relic of Yu'lon. Took it out, BoE. Score.
TLDR
1) Item restoration
2) Delete mail with item attached
3) Quickly make a ticket saying what happened (silly mistake, embarrassed etc)
4) They will most likely make an exception and mail it again
5) Profit
I approve.