As per subject. This is hard to trace for me because they are put in a "spam" folder in the webmail interface which I hardly ever use. One of thes is e.g: linux-audio-user(a)lists.linuxaudio.org ISP says this is correctly marked as spam because it doesn't have "standard features routing / resolution / related to domain" (I'm translating this from Italian. And in a further email that they check "correct routing of the sender in relation to DNS domain and not only reverse etc." (again my translation). Any mail-admin guru have an idea about this? Of course it would help if they simply had an option to whitelist addresses ("this is not spam") or something similar which they seem not to have. Lorenzo.