I have been given the task of setting up a backup mx server for my work. I would like to use postfix for this as I am most familiar with it. But if there is another MTA more suited to the task I would be willing to learn it. The backup server needs to relay the mail to the main MX but also deliver a copy locally so it can be checked via POP. What would be the best way to achieve this? I think I have worked out how to do this in theory and I have the relay part working. But there are a few areas that I'm not sure about. 1) Is it possible to remove the email from the mailbox when it has be successfully relayed? 2) How can I stop postfix bouncing emails when they can't be relayed on. 3) I was thinking of using recipient_bcc_maps, is there a better way of doing this?