> -----Messaggio originale-----
> Da: John Rudd [mailto:jrudd@ucsc.edu]
>
> Giampaolo Tomassoni wrote:
> > Hi everybody,
> >
> > anyone knows of a SA plugin to score mails based on challenging the

> sender
> > e-mail?
> >
> > I don't mean C/R, but instead just attempt an SMTP session in order

> to see
> > if the source mailbox is known to the sending domain's MX. If it

> isn't, the
> > plugin applies a score to the e-mail.
> >
> > I know I could do something like this in my postfix, but this way I

> would
> > totally reject e-mails carrying a wrong From: header. Since some

> people seem
> > to be a bit dyslectic in writing its own e-mail address, I would

> prefer not
> > to reject unless there are some other reasons too (i.e.: the mail

> hits some
> > other SA rules).

>
>
> Doing it at the MTA is called "Sender Address Verification",


Oh, yes. That's it. Tank you: I couldn't recall its name.


> and isn't
> considered to be that much better than C/R (it doesn't clutter a
> forged-sender's mail box, but it can bog down a forged-sender's mail
> server with verification requests).


Well, it may be. I know, however, that a lot of people is doing this at the
MTA level in order to reject mails with forget sender.

Also, SAV's drawbacks may probably be mitigated by caching the results.


> I wouldn't expect a sender verification plugin for SA to be any better
> liked than doing it at the MTA level.


I don't mind to do something more polite with MXes or better effective than
its equivalent at the MTA level. I would like not to trash incoming mails
solely because they failed a SAV check, thereby I would need a SA plugin for
this.

Giampaolo