What if it was possible to specify an alternate remailer? In the case that a remailer went down, you could specify an alternate. For example:
[ Snip! ]
If foo.com was down, the message would be delivered to bar.com instead. The PGP message would have to be readable to both of them, so it would decrease security, but reliability would be better, especially for reply blocks. Comments?
Hmmm. Not as secure, but how about this... (a kind of script) begin A if active(mailer@foo.com) mail(mailer@foo.com,B,C) elseif active(mailer@bar.com) mail(mailer@bar.com,B,C) end begin B { next block of scripts for chain... remailer would encrypt B and C blocks for appropriate mailer } end begin C { this block would be cargo... could even contain multiple messages? } end That's a pseudoscript, but you get the idea... (no pun intended ;)