From Aeria Browser Wiki
Note: Mailbox feature is currently disabled.
Players can send and receive mail via the Mailbox inter face. You can also sell and trade items with other players using the mail system.
Mail List: Display all mails sent to you from other characters.
Unread Mail: Filters out all the mail you have already read to show just unread mail.
Sent Mail: Displays all the mail you have sent out to other players.
Select All: Allows you to select all the mail currently displayed so you can manage them at the same time.
Delete: Deletes all selected mail permanently. Once you delete a mail, you can not get it back.
Get Attachments: Collects all of the attachments of the selected mails at one time.
Write Mail: Allows you to write a letter to another player. You must know their correct character name to send them a mail.
Reply: Only available once you have selected a mail that was sent to you. Always you to reply directly to a player who has already mailed you.
Return Mail: Allows you to refuse a mail, mostly used when they send you a Pay for Mail.
Cancel: Click to exit the Mailbox interface.
Special Mail Types: Game Master Mails: Special mail from the GMs that are marked with the letters GM. These may contain special prizes or news about events and updates.
Unread Mail: Mail that hasn't been read yet is marked as "Unread"
C.O.D Mails: Specially marked mail requires you to spend coins to receive the items that were sent as attachments. Be careful when selecting these letters.
Composing a mail: Recipient: The name of the player you are sending the letter to. A drop down arrow will allow you to select one of your previously added buddies instead of remembering their names.
Subject: Keep the subject of your letter short so people know what your letter is about.
Body: This is where you include the bulk of your letter. Make sure you don't run out of space!
Attachment: Drag and drop items from your backpack over into the letter to add as attachments. You can send items from both your Equipment and Items sections.
Pay for Mail: Select the small check box in the bottom right corner of the mail interface to have the player you send the mail to have to purchase the items you included as attachments. You can set the price for your attachments by filling in the text box just under the Attachments. You can only fill in this box once you marked the mail as "Pay for Mail". You can also choose how long you want the mail to remain active before it automatically returns to you in either 1 hour or 6 hours by selecting that option just under the "Pay for Mail" check box.
Coins: Here you can set the price for your attachments by filling in the text box just under the Attachments. You can only fill in this box once you marked the mail as "Pay for Mail".
Send: Only click this button once you are ready to send your mail.
Cancel: Click to exit the mail composing interface and return to the mailbox. You will lose any message you may have been writing.