How Internal & External Mail Routing Work? Give With Example?When user send a mail NRPC(Notes protocols) to deposit the message into the MAIL.BOX database on the user's Domino mail server.The Router finds the message in MAIL.BOX and determines where to send the message for each recipient. The Router checks its routing table to calculate the next "hop" for the message on the path to its recipients and determines the appropriate protocol -- either SMTP or Notes routing -- to transfer the message.Using SMTP routing, the Router connects to the destination server -- the recipient's mail server, a relay host, a smart host, or one of the servers in the recipient's Internet domain -- and transfers the message.Using Notes routing, the Router moves the message to the MAIL.BOX database on the server that is the next hop in the path to the recipient's mail server. The Router on that server transfers the message to the next hop, until the message is deposited in the MAIL.BOX database on the recipient's home server.The Router on the recipient's server finds the message (in MAIL.BOX on a Domino server) and delivers it to the recipient's mail file