There is gear that is ONLY rare and can not be sent through delivery, such as Osode, or the Hachiryu set. As well as gear that is ONLY EX or RARE/EX and CAN be sent to another character, perhaps as an early test to see what would happen maybe. I don't remember the bulk of the items, but one example would be the Smart Grenade. I know it's not enough to go against the general concept that EX items cannot be sent, but there are exceptions to these "rules."
Also, for those who didn't actually read the original post of this topic (created by Gildrein [MOD]):
There.[dev1002] Delivery System Adjustments
The upcoming version update will see the following changes made to the item delivery system:
Adjustments
It will be possible to send EX items to characters belonging to the same PlayOnline account.
The list of deliverable EX items will be expanded gradually in order to maintain game balance and ensure that proper testing is conducted.
Can only be sent to other characters of your own POL account.
By game balance, I'm sure it's referring to the idea of obtaining certain Rare/EX gear that wouldn't be accessible to, say one of your mules, by sending it from one of your main characters via delivery (or any other method for that matter). More than likely delivery options will be limited to items and equip that can already be traded - at least in the early stages of this development. Don't take my word for it, but tell me if that doesn't make sense to you.
Anyway, the basic gist of what I'm trying to say is don't jump the gun and presume your assumptions are always correct when we haven't been given the full details of this information. Perhaps a moderator would be kind enough to confirm a few things to make this idea clear to everyone.