BUG: Moogle Delivery Error "Unable to send mail"

[Rivaru]

Time: October 04, 2013 around 11:40 AM GMT+8
Frequency: All the time since it started...
World name: Tiamat
Character name: Myria Rivelle
NPC name: Delivery Moogle
Monster name: NA
Class/level: Blacksmith/30 (Virtually happens regardless of the class I switch into...)
Party or solo: Solo
Race: Miqo'te Female
In-game time: 11:00 AM (Eorzea Time)
Area and coordinates: Uld'ah/Gridania/Limsa Lominsa Moogle Delivery NPC Location

Problem:
A friend of mine (Shiro Yasha) asked me to make 15 units of Iron Claw Hammers (Blacksmith Craft Items). When I finished, I decided to mail him the items since he was offline. I was able to mail the first 10 items smoothly. However, I started encountering the "Unable to send mail" error when trying to send the last 5 items. At first, I thought I may have reached a limit on sending Moogle Mails. However, there doesn't seem to be any limit indicator when I checked the Mail Window so I concluded that it might be some kind of bug. I have tried Delivery Moogles in Ul'dah / Gridania / Limsa Lominsa towns to no avail... I haven't tried mailing to a different person.


Laptop Specs
-=-=-=-=-=-=- System Information -=-=-=-=-=-=-
OS: Windows 7 Ultimate 64-bit (6.1, Build 7600)
GFX: Nvidia GeForce GT 540M
Processor: Intel Core i5-2410M CPU @ 2.30GHz
Memory: 6144MB RAM
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Browser Information
Name and version of the browser currently in-use: Google Chrome
Internet Explorer Version: N/A