Viktor Dukhovni: > > On Nov 1, 2018, at 11:30 AM, Bill Cole > > <postfixlists-070...@billmail.scconsult.com> wrote: > > > > I intend to experiment with postscreen on 587 on the next Postfix > > system I work with where compromised accounts are a problem. > > Don't waste your time. Postscreen cannot help you with this. > Postscreen maintains dynamic IP-address whitelists/blacklists, > which are of little use in submission, because submission users > routinely use dynamic IP addresses. > > Also MUAs are interactive, and users are not terribly fond of > having their mail submission temporarily rejected and having > to try again later. Postscreen never accepts a message on > the first try when the IP address is not already whitelisted.
That depends. I don't use 'after 220' tests, and never have client forced to reconnect. > Postscreen also gets most of its effectiveness from RBLs, > these too are not terribly appropriate for submission, as > legitimate submission users will dynamically get IPs that > botnets have previously abused. > > You probably know all this, and perhaps you'll still be able > to figure out some usable deployment model, but I'm not > optimistic... I think that there are DNSBLs that explicitly target bots, so a remote IP address may get flagged for that (whether it will be flagged soon enough is a different matter). Wietse