We are using CiviMail, but I'm a bit confused on the purpose of the FROM field when sending mailings. We have about four different email addresses set up in the CiviMail From Email Addresses screen, all with the same domain for different administrators. However, no matter which FROM address is used, all the sent mail uses the same mailbox for sending. So when we look at our sent items folder, even if we used a different email address in the FROM field, it still uses the default mailbox.

Is it not possible to use the mailbox associated with the FROM address when sending mail using CiviMail? Or will it always use the mailbox that is specified in the Outbound Mail screen, no matter which FROM address is specified?