[isp-tech] Re: Postfix wierdness...

["Farrell Christeson" <spamthis@...>]

Can you not send to them at all even after four hours or do they just always
refuse the first connection attempt ? Some mail services are starting to use
GrayListing to slow/fight spam. Graylisting refuses the first connection
attempt after getting the source server , sender and recipient information.
It works by assuming that a lot of spam from infected / bogus mail systems
will not attempt to resend. Once an email has been re-sent , the GrayList
system adds that  combination of "source , sender , recipient" to a list and
then basically WhiteLists that combo.

Farrell Christeson

----- Original Message ----- 
From: "Chris Wathan" <cwathan@...>
To: <isp-tech@isp-tech.com>
Sent: Saturday, September 25, 2004 6:01 PM
Subject: [isp-tech] Postfix wierdness...


>
>
> > Hi everyone,
> >
> > I have what is hopefully a question with a quick and simple solution.
> > Postfix is installed and running on a box.  It can send to some
> > domains fine each attempt.  Other domains it logs "connection refused"
> > or "operation timed out".  Telnet'ing to port 25 on the same boxes
> > instantly connects me and displays the mailserver header.  The worst
> > of the culprits are domains using yahoo and hostsave as their
> > mailservers.  Could anyone shed some insight into this?  Again, I have
> > no problem connecting to some servers with postfix but others give me
> > errors.  Yet, telnet'ing to port 25 to said problematic servers on the
> > postfix server results in instant connections.
> >
> > Thanks,
> > Chris Wathan
> >
>
>
> ______________________________________________________________________
>
> ISPCON Fall 2004 - Santa Clara Convention Center - Nov. 3-5 - This fall's
conference kicks off
> with deep-dive workshops, keynotes from people like Nigel Ballard of
Matrix Networks and Jeff
> Pulver of pulver.com, a six-track conference program and a massive exhibit
hall full of the
> hottest technologies and tools for your wired and wireless ISP business.
> Register early and SAVE. Visit www.ispcon.com for complete details.
> ______________________________________________________________________
>




>
> To unsubscribe via postal mail, please contact us at:
> Jupitermedia Corp.
> Attn: Discussion List Management
> 475 Park Avenue South
> New York, NY 10016
>
> Please include the email address which you have been contacted with.
>
>


         _____________________________________________________

         ** ISPCON Fall 2004 - Santa Clara Convention Center **
         ** The ISP and WISP event - http://www.ispcon.com  **
** Register at the current rate and bring a buddy too for only $350. **
        ________________________________________________________






To unsubscribe via postal mail, please contact us at:
Jupitermedia Corp.
Attn: Discussion List Management
475 Park Avenue South
New York, NY 10016

Please include the email address which you have been contacted with.