Protection just might not suffice after all. Still, with the appropriate care, an anonymous server might be fine for more routine kinds of whistleblowing, especially if you also use encryption. Privacy-minded people on the Net seem happy on the whole with the performance of the anonymous servers. The main drawback so far seems to be that some messages may be delayed too long because the servers are so popular. Also, some servers overseas have faced police raids.
Nothing is absolutely secure.
For general information, check out alt.privacy or the Yahoo listings on anonymous remailers . So much for private e-mail.