Re: [exim] ACL to allow differen users differnet message siz…

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Autor: Philip Hazel
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A: Mark Ter Morshuizen
CC: exim-users
Assumpte: Re: [exim] ACL to allow differen users differnet message sizes
On Thu, 26 Oct 2006, Mark Ter Morshuizen wrote:

> Hi,
>
> Can anyone help me with an acl to allow different users different message
> sizes. What I would like to do is have a list of users and their allowed
> message sizes (local_message_sizes) like so:


You cannot make this work reliably.[*] In the RCPT ACL, where you have each
recipient, the value of $message_size is what the sender said it was,
not what it really is. So you have to trust the sender. Sometimes the
sender won't tell you a size in advance, so you are even worse off. By
the time you have received the data, and therefore know the true size,
you can no longer reject individual recipients. This is a limitation of
SMTP. It's too S.

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[*] Unless you accept only one recipient per message and delay all the
rest, which raises its own problems.

-- 
Philip Hazel            University of Cambridge Computing Service
Get the Exim 4 book:    http://www.uit.co.uk/exim-book