On Thu, 2006-10-26 at 19:07, Tim McCormack wrote: > Many Tor exit nodes block port 25 because spammers sometimes try to use > Tor. For anonymous mailing you could try Mixminion instead of Tor.
I understand the need for controlling spam. If you don't control it, the recipients will often block you. Even if you're not blocked no legitimate organization or tool wants to be identified as supporting or enabling spam. The Mixminion project seems to be stalled, as they have not released any new software in almost 11 months, even though it is described as alpha software. In the Overview of Tor, http://tor.eff.org/overview.html.en, the "Why we need Tor" section states "It can even threaten your job and physical safety by revealing who and where you are. For example, if you're traveling abroad and you connect to your employer's computers to check or send mail, you can inadvertently reveal your national origin and professional affiliation to anyone observing the network, even if the connection is encrypted." The same logic would apply to any military or government employees, dependent on local communications. The "Tor: The Second-Generation Onion Router" design document http://tor.eff.org/svn/trunk/doc/design-paper/tor-design.html mentions using SpamAssassin in section "6.2 Exit policies and abuse" on Tor exit nodes. I'm curious if the current default on exit nodes to block port 25 is a temporary expedient due to the very limited resources available to the Tor project? Do the developers hope at some point to be in a position to enable anonymous email through the Tor network, either by blocking individual spam messages at the exit, or blocking spam sources by IP address from the entry nodes? The latter should involve a much lower overhead, but at the risk of blocking legitimate users. Perhaps blocking only the better known, high volume spam sites would substantially reduce the load on the Tor network while minimizing the impact on legitimate users. George Shaffer