可能是对方换地址了

对方注销账号了

可能是对方换地址了，然后postcrossing给你登记的？

后续：我看到这个用户状态显示正常，就发了邮件问了一下~如下：
“Hi, 她的名字
I have a card send to you 5 days ago, I haven't send it yet (sorry about that, I'm waiting for my stamps I bought ) but you register the card today （No. CN-明信片编号）. Don't worry I will still send the card to you anyway, but I just want to make sure if you change your address or if everything is OK.
At the best
我的名字”

今天收到回复如下
“Hello,
Sorry, I haven't got your postcard yet.
I'm looking for the ID from China and asked admins to help me.They gave me your ID. But it's not the same ID I'm looking for.
Besides, as you can see the time of shipping is 5 days, it's impossible. I'm sure it's rather fast for postcards from your country to my. That's why I write this message.
Moreover, I can download the "wanted " card and you can say that it's not yours.
I hope coronavirus passed you by.
All the best,
他的名字”
原来是弄错了ID，今天已经正常给他寄出了~

对方有回你嘛 好好奇啊

我把六楼截图重新传了一下，不知道这样能不能看到了~
我也是蛮懵逼的……我只是礼貌的问了一下地址是不是没问题，如果没问题我就正常寄出，结果给我回了一堆我没有收到你的片啊，还罗列了一二三点理由为什么没有收到o(╥﹏╥)o……我当然知道你没有收到啊，因为那时候我还没给你寄……

然后再后续，我又回了一封，就不发原文了，大概意思是：
你的明信片已寄出，需要photo proof可以留邮箱发给你，如果还需要其他我帮忙的可以尽管告诉我……