Hi, I'm wondering what is the correct architecture and configuration to setup a multilayer mail handling? What I have in mind is something more like what we can found in Web platform architectures.
1. First layer does first checks: user authentication (if mail to be sent), greylisting, RBL checks and SSL offloading. If all checks are OK request is proxied to layer 2. 2. Second layer, will actually handle the SMTP connection proxied by layer 1, no major checks should be done as already made by layer 1. 3. Finally, layer 3 to do some virus checks on received emails and maybe some other things I can't think about. Do you have some pointers on how to set up such a mail stack where each layer can be on multiple other hosts? Best regards, Jimmy
