Your Mailbox stores rewards from daily logins, Guild Tasks, purchases, special events and other rewards in the game.
You can access your mail from the World Map by selecting the mail button on the right side of the screen.
To view your mail select the mail you, then collect the rewards shown by selecting the green Claim button. You can collect all mail at once and see a summary of the total mail by selecting the Claim All button at the bottom of your Mailbox.
Mail expiry and limit
All mail has an expiry date which you can check on the right-hand side of the mail. Most mail expires in 1 week, such as daily rewards or Guild War rewards. Daily login calendar rewards expire within 24 hours.
There is also a limit of 100 total mail in your inbox. For more information on this see mailbox limit.