RE: mostly open issues

At 5:12 PM -0800 11/11/98, Alan K. Stebbens wrote:

> | > Many ISPs run filters on all incoming mail.  Sometimes, forwarding takes
> | > place because of infrastructure changes, system changes, etc., on a
> | > per-domain basis, especially in a managed messaging environment.  Resent
> | > headers should not be inserted because of these system-wide,
> | system-imposed
> | > filtering rules.
> |
> | I would not expect Sieve to be used in these cases.  Existing methods
> | (for example, .forward) would be used.  Sieve is for conditional,
> | message-based actions, during final delivery, on behalf of users.
>
> An example: When one of several domains of users is moved from one mailer to
> another, during the migration phase the former will forward mail to the
> latter, on a system-wide basis.  Using .forward features, or other per-user
> features is neither convenient nor very efficient.
The fact that you use Sieve instead of a .forward file, or a mail 
server configuration change, doesn't change the situation.  Your use of 
Sieve is fine for you, and I'm happy it works for you, but it isn't the 
target for Sieve.  Sieve is intended for user-directed actions during 
final delivery.
> Our product uses Sieve as the system-wide mail filter, specifically for SPAM
> filtering, but it is useful to the system administrators for other purposes
> as well.
There are mail servers which permit sites to install filters or custom 
inspection and actions at two different points: message traversal, and 
message delivery.  Sieve operates at message delivery.  If you want to 
use the same syntax at message traversal, that's fine, but I don't 
think it should drive the syntax, especially when it can unnecessarily 
complicate things.
> In any case, my principal point was that the "forward" action should not
> always insert "Resent-" headers.  I suggested that another action, "resend",
> be defined to apply this semantic.
I would object to that.  Having two different actions, with almost 
identical semantics, seems to me to be a bad idea.  It will lead to 
user confusion, and users will use the wrong one.
If your specific product wants to use Sieve at a stage earlier than 
final delivery, and wants to add product-specific extensions, for 
example, a relay action, that's a different matter.