[Tech] reverse lookup for our IP and RBLs added to Postfix

[Daniel Melnechuk]

I have contacted our colocation vendor and they have changed our IP  
address for reverse lookup to return green-rainbow.org. This should  
help with our sending email to aol and verizon, etc.

I have added Realtime Blackhole List (RBL) checking in Postfix (our  
mail exchanger) and have added about 19 or so RBLs to be checked.  
RBLs are maintained by people on the net trying to fight spam. There  
are many type of lists but the idea is to keep on top of IP addresses  
that have been used for spam and are being used for spam. Yes, large  
ISPs are occasionally put on but they are off quick.

The way Postfix uses it is when a connection comes in to deliver  
email to our system, Postfix takes the IP address and asks each of  
the RBL sites if the IP address is on the list. If so, it rejects the  
connection from the computer.

When i recently tripled the number of RBLs i was using spam email  
delivered to me went down dramatically.

Anyway, just thought you should all know. The README file in /usr/ 
local/etc/postfix explains it a bit.

Peace,
Dan