On Fri, 27 Jun 1997, Paul Vincent Craven wrote:
I would not want to tell a novice user how to delay mail using a cron job! My
thought was that a client could add a line to the message such as:
x-delay-mail: blah blah
I interpret "x-" as meaning "this is a proprietary non-interoperable
extension." It's very overused. It's also the wrong layer -- an SMTP
relay isn't supposed to look at RFC 822 headers.
And the SMTP server would not forward the mail until the specified time was
reached.
There are a number of serious security issues involved with this which
were discussed on the DRUMS mailing list. Rough concensus was that it's a
really bad idea on the server -- it belongs in the user agent.
Outgoing rules could also allow a company could forward a copy all
messages that employees send to the competitor's domain to the office
manager, etc.
That has very serious legal implications, so it's probably best done by a
proprietary mechanism (preferably undocumented so people don't get
themselves in legal trouble by accident).