Re: coding antispam

Giganews Newsgroups
Subject: Re: coding antispam
Posted by:  Pierre Roux (pier…@openwater.co.za)
Date: Sun, 17 Dec 2006

Use your normally assigned DNS server. You'd have to set this as a
configuration.  It's a good idea to have a couple of DNS servers available
for redundancy.

Any server not using Port 25 for incomming SMTP connections, is
non-standard, and could be seen as not accepting mail in any case, thus, for
your purpouses, an invalid server.  The option to not hardcode port 25 just
makes your application easier to use in non-standard implementations.

"Lucian" <thanks@nospam.com> wrote in message
news:7962AFA59513E340thanks@nospam.com...
> Hi,
>
> I am trying to reduce the spam I get and so far what I understood is
> that I should be verifying the email address from the actual spam
> email, the field reply-to. I thought of doing this:
>
> 1. use TIdDNSResolver and a querytype = [qtMX]. I did that using
> various DNS Servers for the Host property, however I am not clear which
> exactly DNS server I should use?
>
> 2. Anyway, I can get the mail servers from the TMXRecord.
>
> 3. With that mail server, I understood I should be using a TIdTCPClient
> and than try to: connect to port 25, than send HELLO, MAIL FROM and
> RCPT TO commands and examine the results for each of them. If they
> return ok than the email addresss would be a valid one and I would
> delete any other email having invalid an email address.
>
> However, hardcoding port 25 into the equation is not realy a solution
> since many servers outthere probably don't use that.
>
> Anyone knows how I can solve this?
>
> --
>
> regards,
> Lucian

Replies

In response to

coding antispam posted by Lucian on Sun, 17 Dec 2006