RE: [Exim] How to use script to validate address

On Tue, 17 Sep 2002 11:38:20 +0200 Jan Martinek wrote:

Hi,

Just a few thoughts that you might think about. Actually we do just
what you want to do.

> Hello,

> I would like to configure Exim to become an "SMS gateway".
> It should proceed mail addressed to
> xxxxxxxxxx@???

it's useful to introduce a subdomain here: sms.your.domain
(or whatever).

> where xxxxxxxxx is a GSM telephone number. I cannot
> use any list, because there are lots of possible numbers,
> but I can do a script that can check telephone number validity
> and eventually send SMS.

and you probably also want to do some other checks, unless
your system is free of charge and you don't care about
misuse, but you probably do. What if
- the sender is a random internet user that "discovered" about
your service?
- an authorised sender stupidly forwards all his mail to
his cellphone?
- some administrator uses your service to send alerts to
his cellphone, and for some reason his alert system goes
berserk and starts shooting out messages like a tommy-gun?
These are just a few thought that you should consider before
going live.

> So Exim should do the following things:
> if the mail address is not local, pipe it to the script.
> The script is able to send the mail as SMS if the number
> is valid.
> If the script returns non zero (invalid number),
> go on proceeding the mail normal way - probably resulting
> in "Unknown recipient" or something.
> Is it possible to do it somehow?

Bernard Stern, SWITCH