Re: [exim] Really Cool Trick

Stuart Gall wrote:
>
> On 19 Oct 2006, at 21:12, Martin A. Brooks wrote:
>
>> Marc Perkel wrote:
>>
>>> This person only has one user account for the domain with no plans to
>>> ever have more. It's a domain for one person. But he's into IMAP and
>>> likes the idea of direct folder delivery. So if he subscribes to some
>>> new email list what he does is create a folder for that list and then
>>> subscribe using the email address folder@???. The existence of
>>> the folder makes the email address valid.
>>
>> I fail to see the difference between this and delivery to an arbitrary
>> shared folder. Unless I've massively misunderstood what you're doing
>> it's neither a trick, nor cool, it's just a function of your IMAP
>> server.
>
> What he is doing I thing is getting exim to automatically create a new
> account for any local part it receives on the domains it servs.
> That is quite clever.
> However, Marc, there is a huge problem (Assuming I read this right).
> When the domain gets its first dictionary attack (sending spam to
> loads of random local parts)
> You will create hundreds possibly thousands of new mail drops.
>
>

Actually that isn't the case. The IMAP folder has to already exist so if
someone does a dictionary attack then any local part that doesn't match
a folder will be rejected as an unknown user. If the folder already
exists them mail is delivered into that folder. If it doesn't exist
isn't not created.

Thanks for calling it clever. I'm really liking it.