[NCLUG] comcast blocking port 25?

[Bob Proulx]

DJ Eshelman wrote:
> Now for the question:
> Is it possible for mail from a dynamic IP to have a reverse DNS
> entry?

Not usually.  It is possible if the folks authoritative for that IP
address block allow and enable dynamic dns updates.  This is typical
on the local network but I have never seen the big ISPs provide that.

> How did you go about detecting if it was from a Dynamic IP or not?

The dul.dnsbl.sorbs.net RBL provides a reasonable list.  At least I
have not had any problems with it.  I am sure it is not perfect though
because I don't see how anything could be.

  http://www.au.sorbs.net/faq/dul.shtml
  http://www.au.sorbs.net/using.shtml

Bob