LinuxQuestions.org
Help answer threads with 0 replies.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Security
User Name
Password
Linux - Security This forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.

Notices

Reply
 
Search this Thread
Old 12-02-2003, 01:58 PM   #1
sirjosi
LQ Newbie
 
Registered: Oct 2003
Posts: 24

Rep: Reputation: 15
postfix header check


environment:
redhat 9
postfix
pop before smtp


Ive set up header check to bounce back anything going to a certain person, say

/^to: aaa@aaa.com$/ REJECT (aaa.com being a valid virtual domain)

I then mapped this email to my user name to see if it is still receiving any emails. When I try to send from yahoo to aaa.aaa.com, it gets rejected (yay!)

Yet Im still getting spams to this address. How are they getting in? To make matters worse, I'm also getting aaa@bbb.com where bbb.com isnt even on my domains list

thanks for any help
 
Old 12-02-2003, 02:40 PM   #2
chort
Senior Member
 
Registered: Jul 2003
Location: Silicon Valley, USA
Distribution: OpenBSD 4.6, OS X 10.6.2, CentOS 4 & 5
Posts: 3,660

Rep: Reputation: 69
The RFC821 and RFC822 headers don't have to agree. What you're filtering on is the RFC822 (message header) but in order to get the message to you, only the message envelope needs to point to your address.

I think Postfix has support for user maps. You could always point that user to /dev/null.
 
Old 12-02-2003, 07:07 PM   #3
sirjosi
LQ Newbie
 
Registered: Oct 2003
Posts: 24

Original Poster
Rep: Reputation: 15
thanks however, this rule should apply not just for existing users right?

Im actually using this header check to make my catchall account easier to browse through for valid emails that may have been sent to the wrong email address say aaa1@aaa.com. Our clients just love us for catching these types of good emails.

Therefore I cant just point a user to a null destination
 
Old 12-02-2003, 07:11 PM   #4
chort
Senior Member
 
Registered: Jul 2003
Location: Silicon Valley, USA
Distribution: OpenBSD 4.6, OS X 10.6.2, CentOS 4 & 5
Posts: 3,660

Rep: Reputation: 69
Ahh, so you're directing the "left overs" that don't go to an actual user into a catchall account? Right, you do not want to /dev/null your catchall. However, you should be able to setup a usermap and "create" the invalid user, and direct just that user to /dev/null. *DISCLAIMER I haven't done this with Postfix so it's all a theory, but it's a theory based on about 7 years of e-mail administration.
 
Old 12-02-2003, 07:17 PM   #5
sirjosi
LQ Newbie
 
Registered: Oct 2003
Posts: 24

Original Poster
Rep: Reputation: 15
but that would mean having to make a bunch of non real users just to throw away the bad mail, this isnt so bad but we may be talking about tens to hundreds of bogus users

It would be really nice to have the to: caught by the above syntax or any other means
 
Old 12-02-2003, 08:07 PM   #6
chort
Senior Member
 
Registered: Jul 2003
Location: Silicon Valley, USA
Distribution: OpenBSD 4.6, OS X 10.6.2, CentOS 4 & 5
Posts: 3,660

Rep: Reputation: 69
You can do that only if the filter hooks into the MTA to read the RCPT TO: rather than just scanning the To: on the message header. The SEIVE filter in Qmail will let you do the former. There must be something similar in Postfix, but like I said, I'm not familiar with it.
 
Old 12-02-2003, 08:09 PM   #7
sirjosi
LQ Newbie
 
Registered: Oct 2003
Posts: 24

Original Poster
Rep: Reputation: 15
this sounds like a good lead.

thank you so much
 
  


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 my Postfix got hacked? How to check? woranl Linux - Security 6 07-26-2005 05:52 PM
Partition check, check double check Vincentius Linux - General 0 12-25-2004 06:47 AM
c header files in linux in place of header files in windows? harun_acs Programming 1 03-17-2004 03:24 AM
Boot disk; check. CD in drive; check. Doesn't work; check. Hal DamnSmallLinux 7 02-04-2004 03:10 AM
postfix configuration check Robin01 Linux - Software 0 01-28-2004 07:33 PM


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

Main Menu
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
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration