Orien Lightning Post
The Orien Lightning Post is the mail system in DDO. Mailboxes are available in most Stormreach districts. No mailbox is available in Korthos. Guilds of sufficient level can add a mailbox to their Guild Airships. In game canon, the mail service is run by representatives of House Orien.
Characters can send off-line messages via text to other characters on the same server (only), including other characters on the same account, for a nominal fee of 1 silver piece. It is also possible to send unbound items through the mail, 1 per message, which costs and additional 2% of the listed base cost of the item. Currency can be sent as well, up to "9,999 PP, 9,999 GP, 9,999 SP, & 9,999 CP", a maximum of just under 11,109 PP per message, without any extra charge. Text, item, and coins can be combined in the same message.
Use the first name only of the recipient, as every first name is unique across the server. So, if sending mail to the character "Mo the Mountain Man", just address it to "Mo".
Items from the Auction House and Shard Exchange that you have successfully bid on, your own expired items not bid upon, and refunds (when you are outbid on a sale) and winnings (when your auction is sold) are all automatically sent to your mail box. If you cancel an item for bid, that too is returned to your mailbox.
As mail is received it has a timer count down that starts at three weeks and decreases each day, to indicate how long it has been sitting in the mail box. Once a message is viewed it has a new timer of five days. In both cases when the timer reaches one day left, and beyond, nothing bad happens. No mail is lost. Upon viewing a piece of mail you can remove the item, cash, or astral shards it contains, but if you leave them in the mail, they will not disappear.
Mail is sorted into two separate bins: "Confirmed" and "Unconfirmed". Confirmed mail comes from the system (Auction House sales or expired auctions, NPCs notifying you that you have reached a new favor landmark, etc.), or guild mates and people on your Friends list. Unconfirmed mail is from people who are neither in your guild nor on your Friends list. If there is mail in either of these, "Confirmed" or "Unconfirmed", that tab will have an asterisk visible after its title.
Your mail box can become full at 50 items, which prevents you receiving mail from other players (the mail is immediately returned to the sender), but you continue to receive all system messages and all messages from the Auction House and Shard Exchange. A full mailbox will also prevent you from placing bids on or buying out items from the Auction House, although you can still receive items from the Auction House (which will cause more than 50 items to appear in your mail). Clearing out and deleting mail corrects this problem, although if many items have arrived via the Auction House, it can require more than just a few deletions.