LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 01-29-2015, 11:53 AM   #1
battles
Member
 
Registered: Apr 2014
Distribution: Debian GNU/Linux 7.5 (wheezy)
Posts: 258

Rep: Reputation: Disabled
DROP?


We have emails coming into our server that are then passed on to another server (this is not a virtual server). The server the emails are passed on to is permanently down. We are not allowed to bounce or send any notice back to the original sender. This is causing our mailq to continuously build up with undeliverable mail which I have to continuously delete. I thought the if I put in an 'iptables -A OUTPUT -s 123.456.789.1 -j DROP', that that would cause anything being sent to 123.456.789.1 to be simply dropped. But the mailq is still backing up to this address. I am guessing that postfix is trying to do something ahead of the firewall that is causing this. Any suggestions, rerouting to dev/nul or something like that?

Thanks.

Last edited by battles; 01-29-2015 at 11:55 AM.
 
Old 01-29-2015, 05:54 PM   #2
Ser Olmy
Senior Member
 
Registered: Jan 2012
Distribution: Slackware
Posts: 3,347

Rep: Reputation: Disabled
You can't get rid of application data by dropping network packets. The mail server will attempt to deliver mails according to the way it's configured, and by preventing it from contacting the recipient server, you've only ensured that the mails will stay in the queue until they are removed by some other action (manual deletion, automatic deletion with NDRs etc).

You need to reroute mails, not network traffic. Since you're using Postfix, perhaps the method outlined in these articles could be used.
 
Old 01-29-2015, 06:03 PM   #3
battles
Member
 
Registered: Apr 2014
Distribution: Debian GNU/Linux 7.5 (wheezy)
Posts: 258

Original Poster
Rep: Reputation: Disabled
Thanks. I thought that I had discovered my mistake and tried this: iptables -A OUTPUT -j DROP -d 123.456.789.1, but as you have pointed out, that isn't working either.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Is it necessary to drop specific flags in IPTABLES with an INPUT DROP policy? rootaccess Linux - Networking 5 08-22-2012 08:10 PM
packge drop barthunder52 Linux - Software 0 07-06-2012 10:37 PM
Drop connections to port 80 at firewall machine also drop at protected network? Niceman2005 Linux - Security 2 10-27-2005 08:21 AM
iptables - drop all -> allow needed OR allow all -> drop specific lucastic Linux - Security 5 12-21-2004 02:07 AM
DHCP drop? Duren Linux - Networking 2 10-05-2003 11:49 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 07:05 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration