Hi Wietse, thanks for addressing this issue, a scaling solution for this problem will be really appreciated.
We are an E-Mail Marketing provider and offer a hosted solution for a broad customer base for which we want to be able separate the reputation (so individual customers can take part in reputation systems for content originators as opposed to sending servers, and those often require dedicated IP addresses). On Sunday 22 November 2009 16:42:41 Wietse Venema wrote: > Finally, this is not the only way source IP address selection can > be implemented. [...] > 3) New access/header_checks/body_checks actions that set an SMTPSOURCE > attribute and that is used only by the SMTP client. This decouples > source IP address selection from the sender envelope address, > and requires no transport selection. As a user with limited knowledge of the internal infrastructure of Postfix, I like this option best. For my understanding, outgoing SMTP configuration parameters and mail routing are logically separate concerns, and it is easier to understand if these are configured separately. More important, we need to tune other parameters (destination concurrency, timeouts, ...) based on the recipient domain. So only a way of combining sender and recipient specific configuration solves our problem completely. This option 3) seems to offer the greatest flexibility in this regard. > > Feature 3) while it appears straightforward, it also completely > ignores the existing infrastructure of transport and nexthop > selection. Which, as said above, can be seen as a good thing from a user perspective. > It has the appeal of a short-sighted^h^h^h^h^h^h^hterm > solution and needs more analysis to understand its implications. One thing that comes to my mind: there are anti-spam measures that want the reverse lookup of the sending IP address to correspond with the SMTP HELO hostname. I know that this is not required by any standards, but some providers use such rules to at least give bad score to non-complying senders. An example is UCEProtect, which is used quite often in some parts of Germany. Therefore it would be necessary (or at least desirable) to not only select the source address, but also the HELO name. > > Wietse Rainer -- Software Developer ------------------------------------------------------ Inxmail GmbH Wentzingerstr. 21, 79106 Freiburg, Germany Tel: +49 761 296979-0, Fax: -9 rainer.f...@inxmail.de, www.inxmail.de Handelsregister Freiburg, HRB 5870 Ust.-ID: DE198371679 Geschäftsleitung: Martin Bucher, Peter Ziras
