Re: Sandy and the Doc

[WinSock Remailer <winsock@rigel.cyberpass.net>]

Bill Frantz <frantz@netcom.com> writes:

> I hope if such a system is set up, people who use it will realize that
> email is not 100% reliable.  Just because algebra.com sent mail to
> toad.com, doesn't mean that toad.com actually received it.  A small
> fraction of a percent of these messages will be lost.

Failing something catastrophic like a disk failure or a host down for
more than a week, this should not be the case.  Almost every site
running sendmail has the Os ("SuperSafe") option set.  That means
sendmail will not respond to a "." at the end of a DATA command with
SMTP code 250 until it has written the incoming message (and queue
info) to disk and called fsync.  Thus, you may get 2 copies of a
message, but mail messages should not just disappear regularly at all,
even if the network goes down or a machine crashes.

Non-sendmail MTA's tend to be even more strict about this, not even
allowing this behavior to be disabled.