Reverse DNS Question

[tariq198487 at hotmail.com (Tarig Yassin)]

Dear janes

as I know many services use reverse lookup as a sender authentication technique.
e.g. Email server using  this technique to reduce spams.( if the ip adress of sending smtp server has no reverse lookup it's messages will be considered spam).

regards,

> Date: Tue, 20 Apr 2010 16:08:04 -0400
> Subject: Reverse DNS Question
> From: jamesmartin at ieee.org
> To: nanog at nanog.org
> 
> All:
> 
> In the process of requesting a block of IP's for a client, ARIN requested
> that we list Reverse DNS Servers for the block.  I've never done this
> before, nor have I ever thought it through.
> 
> What is the purpose for this besides resolving name-based reverse lookups?
> Are there any definitive guides out there on how this works (besides the
> ARIN site)?
> 
> I know this is really basic stuff but I don't know it and have never needed
> to know it until now.
> 
> Thanks
> 
> -- 
> __________________________________
> James Martin
> jamesmartin at ieee.org
 		 	   		  
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