Try clicking on it a lot of times. Is this mail from a possible pen pal? Cuz this happened to my sim too. And I clicked like crazy and after a few tries, you will get a notification about the mail. And then the mail just got stuck in his inventory and when I started the game again, it was gone. I realized you cannot place it on the world but you can buy a board to pin your mails. I think the board is under 'activities and recreation' in buy mode. I haven't tried that yet, but maybe you could try that? Good luck.
I had the same thing in the inventory of one of my sims. The bills arrived, but the family couldn't afford to pay just yet so I had her "Get Mail" anyway, and in her inventory there was a white envelope. After her hubby got home from work I paid the bills, but the envelope never left her inventory. I just assumed it was the bills (bugged to stay in inventory or something), mostly because I don't know what other mail Sia would be getting...
The envelope that won't budge is the bugged reward you get for collecting all metals.
If you want to remove it from inventory, just ask pen pals for a few postcards (so game creates a group of these items) and sell whole groups (as the envelope will be in one of them).
I received it, too, and not collecting any metals. I was waiting for postcards, got two, and then the envelope stayed and wouldn't go away no matter what I did. I don't even know if it was supposed to be a bill, as the postcards came on a Tuesday, and the bills are supposed to come on Tuesday as well.
Ordered another postcard. Still the envelope stayed, even after selling the postcard.
Moving in another Sim, as Crin suggested, didn't help anything, and neither did traveling.
Comments
http://sims4.crinrict.com/en/2014/09/bills-stuck-in-inventory/
I've already posted about it here on the forum and reported on EA answers HQ.
Here's the post with the pic:
http://forums.thesims.com/en_US/discussion/comment/12667834/#Comment_12667834
The envelope that won't budge is the bugged reward you get for collecting all metals.
If you want to remove it from inventory, just ask pen pals for a few postcards (so game creates a group of these items) and sell whole groups (as the envelope will be in one of them).
I wasn't doing anything else except trying to complete my collection for days.
It is possible something else also gives you the same bugged envelope, if it happens to me, I'll yell.
Ordered another postcard. Still the envelope stayed, even after selling the postcard.
Moving in another Sim, as Crin suggested, didn't help anything, and neither did traveling.
I decided to load my earlier game and get the mail again from the box. When I take the mail, I can't do anything with it.
So I decided never to get any mail.