Petri IT Knowledgebase Forums
 

Petri.co.il forums Home Forums Start Page Forums Frequently Asked Questions FAQ Member List Members List
Go Back   Petri IT Knowledgebase Forums > Messaging Software > Exchange 2000 / 2003
Petri.co.il is happy to award auglan the title of Most Valuable Member !!!
Register Calendar Calendar Search Petri IT Knowledgebase Forums Search Todays Posts Today's Posts Mark Forums Read

Notices

PTR filtering

PTR filtering

this thread has 13 replies and has been viewed 2315 times

Closed Thread
 
Thread Tools Search this Thread Display Modes
  #1  
Old 11th April 2008, 00:16
scurlaruntings's Avatar
scurlaruntings scurlaruntings is offline
Member
Someone to look up to
 
 Join Date: Apr 2008
  6 month star 12 month star
 Location: London England
 Posts: 975
  Send a message via MSN to scurlaruntings
 Reputation: scurlaruntings will become famous soon enough (87)
Default PTR filtering

Can anyone tell me if MS Exchange 2003 has the ability to discard connections when a PTR record is not present for the sendee. IE if an email is sent from a domain that only has an MX record and not a reverse public record aswell that email would not be delivered and an NDR delivered instead indicating to the sendee that the "said" domain does not accept email from domains with no valid PTR record. I know exchange has the ability to do a reverse look up on the SMTP connector. But this only allows for reverse DNS information to be appended to the message headers which in my opinion is a bit of a useless feature and a possible uneccesary over head on your mail server. Finally assuming exchange doesnt have this feature (which im pretty sure of) is there any open source utility that can be integrated into exchange to allow for this feature.. (why o why is SMTP inherently insecure. Maybe we need a new ratified protocol that can allow for securer SMTP connections.. ok im rambling now..)
  #2  
Old 11th April 2008, 01:05
Sembee's Avatar
MVP Sembee Sembee is offline
MVP
MVP
 
 Join Date: Apr 2006
  6 month star 12 month star
 Location: Newbury, UK
 Posts: 6,201
 Reputation: Sembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud of (1100)
Default Re: PTR filtering

Exchange cannot drop messages based on the reverse DNS record. You will have to use a third party tool to do that. Something like Vamsoft ORF should do that.

Simon.
__________________
--
Simon Butler
Exchange MVP

Blog: http://blog.sembee.co.uk/
More Exchange Content: http://exchange.sembee.info/
Exchange Resources List: http://exbpa.com/
In the UK? Hire me: http://www.sembee.co.uk/
  #3  
Old 11th April 2008, 01:14
scurlaruntings's Avatar
scurlaruntings scurlaruntings is offline
Member
Someone to look up to
 
 Join Date: Apr 2008
  6 month star 12 month star
 Location: London England
 Posts: 975
  Send a message via MSN to scurlaruntings
 Reputation: scurlaruntings will become famous soon enough (87)
Default Re: PTR filtering

Quote:
Originally Posted by Sembee View Post
Exchange cannot drop messages based on the reverse DNS record. You will have to use a third party tool to do that. Something like Vamsoft ORF should do that.

Simon.
Why have MS incooperated a feature in SMTP that most Exchange admins believe adds resilience to there exchange enviroment in terms of combating SPAM? When in reality the reverse look up feature merely adds more information to a message header that could possibly be entirely inaccurate? Seems like a bit of a waste of time to me. I guess its only a small foible as Exchange 2003 is a brilliant product and certainly my favoruite flavour to date. Do you know wether Exchange 2007 will incoperate this feature in SP1?
  #4  
Old 11th April 2008, 02:25
Sembee's Avatar
MVP Sembee Sembee is offline
MVP
MVP
 
 Join Date: Apr 2006
  6 month star 12 month star
 Location: Newbury, UK
 Posts: 6,201
 Reputation: Sembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud of (1100)
Default Re: PTR filtering

You talk about Exchange 2007 SP1 as if it isn't already out. It is, and has been for a while.
The antispam features have been beefed up in Exchange 2007, but reverse DNS lookups is not part of the feature set - you still have to use third party tools.

As to why MS put the option to do a reverse lookup - I have no idea on that. It is a useless option that simply slows down email processing.

Simon.
__________________
--
Simon Butler
Exchange MVP

Blog: http://blog.sembee.co.uk/
More Exchange Content: http://exchange.sembee.info/
Exchange Resources List: http://exbpa.com/
In the UK? Hire me: http://www.sembee.co.uk/
  #5  
Old 11th April 2008, 10:30
scurlaruntings's Avatar
scurlaruntings scurlaruntings is offline
Member
Someone to look up to
 
 Join Date: Apr 2008
  6 month star 12 month star
 Location: London England
 Posts: 975
  Send a message via MSN to scurlaruntings
 Reputation: scurlaruntings will become famous soon enough (87)
Default Re: PTR filtering

Quote:
Originally Posted by Sembee View Post
You talk about Exchange 2007 SP1 as if it isn't already out. It is, and has been for a while.
The antispam features have been beefed up in Exchange 2007, but reverse DNS lookups is not part of the feature set - you still have to use third party tools.

As to why MS put the option to do a reverse lookup - I have no idea on that. It is a useless option that simply slows down email processing.

Simon.
Thats because the last time i supported it it was pre SP1 and over 10 months ago where alot of the functionality had to be done from the command line. Apparently this has been rectified in SP1 and im assuming SP1 has also added other features to what was then released an incomplete product. Incidently last i was aware MS were not supporting exchange 2007 32 bit in a prodcution enviroment. Is this still the case? Or will they have to change there stance because of SBS 2008?
  #6  
Old 11th April 2008, 14:01
Sembee's Avatar
MVP Sembee Sembee is offline
MVP
MVP
 
 Join Date: Apr 2006
  6 month star 12 month star
 Location: Newbury, UK
 Posts: 6,201
 Reputation: Sembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud of (1100)
Default Re: PTR filtering

Exchange 2007 will never be supported in a 32 bit environment. SBS 2008 is 64 bit.

While there was a lot of missing functionality, the service pack did not change the antispam features. The core functionality was there from the start.

Simon.
__________________
--
Simon Butler
Exchange MVP

Blog: http://blog.sembee.co.uk/
More Exchange Content: http://exchange.sembee.info/
Exchange Resources List: http://exbpa.com/
In the UK? Hire me: http://www.sembee.co.uk/
  #7  
Old 11th April 2008, 14:07
scurlaruntings's Avatar
scurlaruntings scurlaruntings is offline
Member
Someone to look up to
 
 Join Date: Apr 2008
  6 month star 12 month star
 Location: London England
 Posts: 975
  Send a message via MSN to scurlaruntings
 Reputation: scurlaruntings will become famous soon enough (87)
Default Re: PTR filtering

Quote:
Originally Posted by Sembee View Post
Exchange 2007 will never be supported in a 32 bit environment. SBS 2008 is 64 bit.

While there was a lot of missing functionality, the service pack did not change the antispam features. The core functionality was there from the start.

Simon.
Wow thats a strange stance. SBS naturally is geared towards small business`s with minimal IT budgets and small long term investments. 64bit SBS will mean a whole new server if the client is considering an upgrade Thats not very good news as clients will hardly embrace the wonders of 64bit computing compared to 32bit instructions..
  #8  
Old 11th April 2008, 14:42
Sembee's Avatar
MVP Sembee Sembee is offline
MVP
MVP
 
 Join Date: Apr 2006
  6 month star 12 month star
 Location: Newbury, UK
 Posts: 6,201
 Reputation: Sembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud ofSembee has much to be proud of (1100)
Default Re: PTR filtering

I think you will find that most SBS purchases are with new hardware, not upgrades. Furthermore if the server is less than two years old then they will already have 64 bit hardware. It is the way that Microsoft are going. All of their server products will be 64 bit only within a few years - I think Windows 2008 is the last 32 bit server OS.

Simon.
__________________
--
Simon Butler
Exchange MVP

Blog: http://blog.sembee.co.uk/
More Exchange Content: http://exchange.sembee.info/
Exchange Resources List: http://exbpa.com/
In the UK? Hire me: http://www.sembee.co.uk/
  #9  
Old 11th April 2008, 15:14
DYasny's Avatar
DYasny DYasny is offline
Moderator
 
 Join Date: Nov 2006
  6 month star 12 month star
 Location: Israel Centre
 Posts: 686
 Reputation: DYasny is a jewel in the roughDYasny is a jewel in the roughDYasny is a jewel in the roughDYasny is a jewel in the rough (310)
Default Re: PTR filtering

my solution to the issue was a linux front end MTA running postfix.

spam levels dropped from 6-7 to single digit numbers, and email traffic has become much lower
________
Buy magic flight launch box

Last edited by DYasny; 6th March 2011 at 20:30..
  #10  
Old 11th April 2008, 15:15
DYasny's Avatar
DYasny DYasny is offline
Moderator
 
 Join Date: Nov 2006
  6 month star 12 month star
 Location: Israel Centre
 Posts: 686
 Reputation: DYasny is a jewel in the roughDYasny is a jewel in the roughDYasny is a jewel in the roughDYasny is a jewel in the rough (310)
Default Re: PTR filtering

as for secure SMTP, it is usually quite enough to drop all non RFC compliant connections
________
Mercedes-Benz Sl-Class

Last edited by DYasny; 6th March 2011 at 20:30..
Closed Thread


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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 On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
AD, DNS, Cisco 2600 serving up DHCP. Reverse PTR records not being removed from DNS. leftleg Active Directory 6 11th April 2008 01:21
Message Filtering mdecourcy Exchange 2007 / 2010 / 2013 4 14th November 2007 18:49
DNS won't create PTR record in Reverse Lookup. trep SBS 2000 / 2003 3 1st November 2007 02:01
web filtering milo974 Windows Server 2000 / 2003 1 11th July 2005 12:07
Spam Filtering ravx Exchange 2000 / 2003 2 29th June 2005 16:14


All times are GMT +3. The time now is 01:34.

Steel Blue 3.5.4 vBulletin Style ©2006 vBEnhanced
Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd.
 

Valid XHTML 1.0!   Valid CSS!

Copyright 2005 Daniel Petri