ISP:
CableOne

Type of Internet Connection:
One that works? D: I jest, Cable

Internet Connection Speed:
5MB

Date & Time:
I think it was around 5pm PST pm Sat. Oct12th

Frequency:
Once; I haven't tried to reproduce this.

Character Name:
Capa Jensen

Race:
Elezen F

World:
Hyperion

Class/Level:
50 Weaver

Area and Coordinates:
Old Gridania, X9, Y8

Party or Solo:
Solo

NPC Name:
Delivery Moogle

Monster Name:
None

In-Game Time:
Unknown, it was yesterday D;

Steps:
I had unfriended someone earlier in the day and they are still able to send me ingame mail; I later blacklisted this person but I am unsure if blacklisting will stop them from being able to send me mail or not (As blacklisting works for more direct means of communication, such as /tell).

It seems that if they don't in turn delete me from their friendlist, they will still be able to continue sending mail... which seems a bit wrong. If this is indeed 'working as intended' then it opens up another way that a player can harrass another.