I've set up the SPF filter that goes with courier-pythonfilter, and it seems to be working fine. Thanks and congrats to Gordon Messner, Jon Nelson, and Terrence Way.

There's one thing, however, that I don't understand. The SPF docs talk about getting users to use SASL so that they can connect to the mail server and post messages from remote sites or from their laptops when they are on the road. I presume that this means that they come in via esmptd-msa on port 587, thereby requiring login authentication.

I have esmptd-msa set up and running, but I don't know how to tell the SPF courier-pythonflter to honor '-all' when users come in via port 25, but to ignore '-all' (i.e., treat it as if it were '+all') when the users come in via port 587?

How can courier-pythonfilter+SPF be set up to offer this differing behavior?

In other words, is there a way to get a courierfilter module to know whether it's running via a port 25 connection or a port 587 connection, and then to offer differing SPF logic?

Thanks in advance.