Peter Salzman wrote:
> Hi all,
>
> I have DSL with dynamic IP. A domain name is attached to my IP, and I wrote
> a Perl script that updates my DNS whenever that IP address changes.
>
> Unfortunately, my ISP filters incoming port 80 and outgoing port 25 if the
> "from" header doesn't contain a "verizon.net" address.
>
I have several similar setups. Though it is more typical for an ISP
to block inbound port 25.
It is extremely difficult to create an IP Packet filter for outbound
port 25 EXCEPT for traffic containing something
not in the first packet. Are you sure you are not relaying through
your ISP's mail server ?
If outbound port 25 is really blocked you can realy off any
mailserver you have control over by using a different port.
Though it would be an excellent idea to either restrict access to
that port in its router or firewall, or exim config.
another alternative is to require smtp authorization on that port.
You can also often relay using smtp auth on an alternate port with
many ISP's. Usually if you are using smtp auth
you do not have to be using an IP that is part of their domain.
Finally there are a number of internet mail services that offer low
cost relaying agin frequently on non-standard ports
>
>
> 1. Since I have a dynamic IP but a constant domain name,
If you have a dynamic IP then it is extremely likely you are in the
SORBS-DUHL and the MAPS-DUL.
And way too many mailservers bounce e-mail from IP's in those
blocklists before using any other means such as SPF
of validating a mailserver on a dynamic IP.
--
Dave Lynch DLA Systems
Software Development: Embedded Linux
717.627.3770 dhlii@??? http://www.dlasys.net
fax: 1.253.369.9244 Cell: 1.717.587.7774
Over 25 years' experience in platforms, languages, and technologies too numerous to list.
"Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction."
Albert Einstein
