Hello Michael,

Well this can cause a serious loss to us, if someone plays around and sends
mail in his manager's name!

I want to stop this.......
Users must authenticate to the server, also the senders email address and
SASL login name must match, and if any user wants to send a mail in his
colleagues name then let then share their passwords.

I checked the
http://www.postfix.org/postconf.5.ht...r_restrictions Markus
posted but I could not understand, I will try and put some more time on this
serious issue tomorrow.

Thanks for all your help. If you have any more links please post.

Regards,

Clifford Gonsalves





"Michael Holtermann" <spamnov2003@gmx.de> wrote in message
news:rkvms1-a5e.ln1@spinnacker.mholti.homelinux.net...
> Hi Clifford!
>
> Clifford Gonsalves wrote:
> > I have noticed that users can send mail in other users name just by
> > setting Outlook mail client email address and display name.
>
> It's not a bug, it's a feature :-).
>
> I really need this feature for my mail accounts. Think about mails with
your
> office-address, sent via a private account. Or vice-versa.
>
> Of course, on the other hand this becomes an issue, where spammers use
this
> feature. It's a really bad idea to bounce suspicous mail to the address in
> the From:-field.
>
> But you're using authentication, so it should be unable to relay mails
from
> untrusted senders.
>
> Do your users send mails with their colleagues names?
>
> Greetings, Michael.