首先,默认的 Tor 出口策略拒绝所有传出端口 25 (SMTP) 的流量。
因此在默认情况下,通过 Tor 发送垃圾邮件是行不通的。
一些中继运营者可能在特定出口节点启用端口 25 。在这种情况下,该计算机将允许发出邮件。但是,那个人可以直接建立开放的邮件中继,完全无需使用 Tor。
简而言之,Tor 对发送垃圾邮件没有用处,因为几乎所有的 Tor 中继都拒绝投递邮件。
当然,这并非全是关于发送垃圾邮件。
Spammers can use Tor to connect to open HTTP proxies (and from there to SMTP servers); to connect to badly written mail-sending CGI scripts; and to control their botnets — that is, to covertly communicate with armies of compromised computers that deliver the spam.
很遗憾出现这种情况,但是要注意,即使没有 Tor,垃圾邮件也已经很多了。
Also, remember that many of their more subtle communication mechanisms (like spoofed UDP packets) can't be used over Tor, because it only transports correctly-formed TCP connections.