duplicate suppression, sieve, loops, redirect and lost email

[Kevin P. Fleming]

> The problem is that these might be different users in some
> installations.  Another problem is aliases.  What if I redirect to
> arm at andrew.cmu.edu and this is an aliases to leg at ...?
> 
> I also haven't thought about how these solutions might work with
> virtdomains.
> 
> I agree that it would be nice to to some behind the scenese magic, but I
> still think that preventing the problem (ie, don't do that) is far
> easier than trying to fix it.
> 

Maybe I'm missing something obvious here, but it can't hurt to ask...

Why can't the duplicate delivery suppression database only store the 
message ids of messages that _actually_ get kept in the message store? 
If a message comes in and is redirected by a sieve script, should the 
evidence of that message even be in the database at all?

If the database only held the ids of messages that had been 'kept', this 
would be a non-issue.