Delivery moogle quest 'Death of a mailman' missing

Hi everyone,

I've seen this thread before but couldn't find the right answer for me. I'm carrier level 11 atm, finished 'Of Siblings and Side-whiskers' and the delivery moogle in Limsa does not reappear. I have already done the Marcette's quests. I have the Twack-a-mole. So that can't be the issue. I'm completely baffled because I really don't know what could be missing. The only side quests I haven't done yet are those in The Tempest. So I'm really hoping one of you could provide me with the right answer so I can be on my way again!!

Thanks in advance!!