Re: [Exim] Limiting Message size

On 1 May 2003 at 18:35, Nico Erfurth wrote:

>
> > At this time I do not see the need (or use) to implement my limits
> > in the DATA ACL as well - as suggested on the list.
>
> You do not know the $message_size while running through the data-acl,
> this is an extension for SMTP, that allows the sending server to say
> "Well, I've 10M of data for you, tell me NOW if you don't want them"
>
> But the sending server does not need to send it. So, the $message_size
> CAN be know when your acl_smtp_rcpt runs, but in some cases you don't
> know it before your data-acl. FURTHER, the sending server can lie
> about the size (I don't know how exim reacts in this case). That
> means, the sender says "I've 1000 bytes for you, do you want them?" -
> Your server answers "Well, 1000 bytes, no problem, I'll take them" -
> the sender gets a big evil grin on his face, and sends you 20 MB now,
> and you'll NOT know the size before the sender finished, and your
> data-acl starts.
>
> Does this make clear why you have to check it in your data_acl too?
>

I fully understand this. But as the data has already been transferred by
the time the data-acl kicks in, it is no use to me stop it, the damage
has been done. Rather deliver the mail (which is local and not
consuming external bandwidth).

Up to now, it seems as if the servers sending mail to me are very well
behaved in this respect. I will act on the baddies in due course.

Thanks for the comment anyway.

Nico