Tomasz, > Traditionally, I've been setting amavis to work with postfix in a > following scenario: > internet -> postfix -> amavis -> postfix -> ... > I have an application which works as a SMTP server on its own, and I've > been contemplating the following setup (no real SMTP server like postfix): > internet -> amavis -> application
> I did a quick setup, and it seems to work correctly. amavisd does implement the SMTP protocol correctly by the book, so this does work, however... > Is this a proper approach? ...it is not a good idea to do so. In a hostile and diverse world of the internet today it takes more than a correct implementation of the protocol to offer a reliable, robust service with good functionality. A mailer serving as an MX needs to handle many concurrent and potentially slow sessions, needs to have access to a list of valid recipient addresses, needs a lot of configurable flexibility in its filtering (consider the vast number of options in the Postfix smtpd_*_restrictions), needs to handle TLS and SASL, ... > Maybe I should rather choose this approach: > internet -> postfix -> amavis -> postfix -> application > Could anyone give some pros and cons of both setups? Yes, this is a sensible approach. If your application can handle the full SMTP or LMTP protocol correctly and in a timely manner you may consider feeding mail from amavisd to the application directly, not via another hop through postfix. If this can not be assured, it is more reliable (but a bit less effective) to go through Postfix, as your diagram shows. Mark
