On-going Internet Emergency and Domain Names

Tue Apr 3 07:56:09 UTC 2007

On 2 Apr 2007, at 21:21, Lasher, Donn wrote:

> Rather, I thought a lot more providers would actually be blocking  
> outbound
> 25 except to their SMTP servers. Just brought up a new mail server  
> for a
> friend; moved an old (14+ year) domain.. I was amazed at the number of
> connections from rr.com, comcast.net, cox.net, verizon, etc etc etc
> obviously not "official" mail servers. I'm actually tempted to start
> blocking anything that doesn't say "mail." in it somewhere.. :)

Lots of people do use the 'came from some consumer isp dynamic range'  
as a reason to block mail by using RBLs which list the entire dial-up/ 
dynamic ranges of ISPs they know about[0], so if you wan to have a go  
at doing that, don't just drop any inbound mail from mtas which don't  
have reverse dns set to mail.something.  At least, not without  
telling your customers that they can outsource their mail to my  
company ;-)

[0] - e.g. http://mail-abuse.org/dul/