Steam – Is it possible to receive a gift on Steam and put it in your inventory if you already own it

I experienced exactly the same thing some time ago.

I have no exact explanation, but my bet is that it's something with steam servers. Either maintenance or some outage. So the only solution would be to just wait for server to go back to normal, unfortunately.

Writing to support might help(or at least give a bit more info) but they do not answer questions quickly and the problem would go away when they would answer, I guess...

I tried sending myself a gift just now - the email contains the sender's email address, indeed. What you can do is send a gift to your own secondary email address, and send them the URL for redeeming the gift (the URL you receive by emailing the gift to yourself) . Hopefully you have some way of contacting them other than their steam profile; for example, give them the url written on a slip of paper.

Caution: The URL contains the email you sent the gift to. If you don't want the receiver to be able to guess who you are, and the secondary email you're sending to is obviously related to you, create a new email account to send to. Example URL, email highlighted:

https://store.steampowered.com/account/ackgift/1F631467BB7E?redeemer=Fadeway%40yahoo.com

With this method, the first time they learn the sender's name will be when they enter the URL into a browser:

If there's no way to transmit the URL to them without posting on their steam profile, that's a lost cause, unless you get a third person to act as an arbiter/organizer who friends everybody and distributes the links while keeping it a secret who sent which one.