Can't recieve items when offline?

May I ask is that a limit to recieve offline object/ notcard please? I ask that as I found that my customers & friends im me & said that they send me objects or notecards, but when I online , I can't find all of them in my inventory. The shame is some even is a no copy items. Also most notecards that can't recieve are my customer's notecard order form. It make me lose many trustworth from my customers as I never recieved there notecard when offline. Can any one tell me how to fix this problem please? tysm