I've seen folder creation and max_recipients permissions 
implementation in IMP CVS today, so I thought I would give it a try 
again :)

But by your argument, any action done by an MTA should/could be done 
by IMP.  For example, IMP could surely be coded to do its own SPAM 
checking, and this would make the spam logs shorter and would cause 
users to think about the kind of messages they are sending.  but does 
this mean that IMP should handle it?



there needs to be some line drawn in the sand as to the limit of 
features we will code into IMP.  preventing duplication functionality 
already present at the mta level seems like a sane line to draw to me 
(and, it seems, to the other developers also).

I know that this must be enforced in MTA level. But it's not difficult 
to implement such permission in IMP too. It would make MTA reject log 
smaller and would enforce users to think about restriction, not as 
about the error in the system but a real restriction to *them*. If you 
know what I mean.

I agree with Kevin, I really think this should stay in the MTA.

At the expense of feature creep, I'd say this belongs in the MTA only. 
  You'd end up with an IMP-only feature that would have to be enforced 
at the MTA anyway, if any other clients were used.  Write policy once 
(in MTA config), enforce everywhere (any mail client).

While this should really be restricted on the MTA level, it would be 
easy enough to add this to IMP.

I came with one idea this morning.



In the company where I work we have a policy, that ex-emploees are not 
allowed to send mail through their mail accounts, only look at it 
another month or so.



So, maybe it is possible to implement "mail send" permission in IMP? I 
think it will be usefull for some people.