Direct Socket to Remailer?

I've heard of telnetting to port 25 to send SEMI-untraceable e-mail. The procedure, quite frankly, sounds rather complicated. Most of my mail that I don't want traced goes through the Mixmaster remailer network. I'm using Winsock-compatible software via a PPP connection. Is it possible, for example, to tell my mailer software to use the remailer itself, such as "remail.obscura.com" as the mail host, rather than "mail.myISP.com"? Will it work, at least for sending, without having an account at "obscura.com", or whatever remailer? Would that be less traceable than sending it through my ISP's mail host?