Borderlands 3 has a mail system which allows you to receive items in-game. In your mail you will find things like rewards from the Borderlands 3 VIP program, pre-order bonuses, or other in-game rewards. However, you need to be able to access your mail to accept and collect these items.
You can access your mail in Borderlands 3 by heading into the social menu for the game, but ONLY when you are in the game and not while you are at the main menu.
If you try to access your mail while at the main menu you will be greeted by message saying it is only accessible when playing. So where do you go to get mail? Basically you’re going to need to go to the exact same Social menu option that you’ll find while pausing the game during play.
Simply pause the game, select social, and then head into the mail section by tabbing over to it.