The mail system in Black Desert Online is slightly different from traditional expectations. You do not use the mail system to communicate with friends, or send and receive items. Instead, it is used for system based communications. You can open the window with the B key (default).
When you sell items on the marketplace, you will receive a mail in your inbox notifying you that the item was purchased. Similarly, when your workers finish promotion tests, or you claim a coupon on your account page, you will receive a mail.
Pearl Shop gifts from other players, Gift of Repayment Letters, profit from Special Deals listings and your House Fame Fund will also all arrive via mail.
When you open a mail with an item or silver in it, you can select the receive button to move it from the mail to your inventory. If the item is stacked higher than 1, you will need to select the amount to receive. You can also send currency straight to the nearest city storage, with the Send to Storage check box. Items and silver can only be received in a safe zone.
As long as the mail has no attachments, you can freely delete it. To delete mail, click the mail to open it in a new window. The Delete button is located in the bottom right hand corner of the new window. You can also click the checkbox next to the mail, on the main mail window, and select Delete, located at the bottom of the window.
If you wish to delete multiple mails at once, you can check each individually, or use the All button, at the bottom of the window, to select every mail on the page you are viewing. You can then select delete. Deleted mail cannot be restored.
If you have multiple mails from Special Deals, you can use the Get All button, at the bottom right of the main mail screen. This will collect all silver from the mails and delete them automatically. If you do not have enough weight for the amount of silver, it will be sent to the nearest city storage.