Re: And so it begins...

[Ken Sims <mdrg5003@xxxxxxxxx>]

Hi Roger -

> One is where someone (like me) has their own domain and their ISP wants
> triple $$$ to host it as compared to one of the major hosting providers.
> If the user's home ISP blocks port 25, as I have heard Cox and Comcast
> have, then they wouldn't be able to send email from their domain since
> it would be via a "foreign mail server." Yes, the ISP could allow all
> "from domains" through their servers but then the reverse lookup
> wouldn't match and it would get marked as spam. Also, if they let
> everything through what stops spammers, except #2 below? BTW, while
> Sprint was in the pre-paid dial up business they also blocked port 25 so
> badly that you could only send mail via a web client which meant only
> from your Sprint address.

Just because you have your own domain hosted on a server on a different ISP 
doesn't mean you have to send through that server.  Except for some 
brain-dead ISPs, you can send email for your own domain through their SMTP 
servers.

Only brain-dead spam-blocking requires the HELO/ELHO name and/or rDNS to 
match the sending domain.  Spam-blocking shouldn't even require HELO/ELHO 
to match rDNS.

The three things that should be true are:
1. HELO/ELHO resolves to the connecting IP address.
2. The connnecting IP address has rDNS.
3. The host name from the rDNS resolves to the connecting IP address.

I have my own mail server on business-class cablemodem service but for 
various reasons have an agreement to relay through the SMTP server of an 
ISP (which is NOT the ISP which provides my connectivity).  All of my email 
has a mis-match between the sending domain and the ELHO/HELO and 
rDNS.  I've never run into a problem.

> Second is a business that has people work at home occasionally. It is
> not often enough to justify a VPN but they need to respond to customers
> and need to use the company's SMTP because the return address is their
> company address. The company exists on another ISP. Home workers are a
> growing portion of the workforce.

Same as above, your ISP should allow you to send email for your company's 
domain through their SMTP servers.

--
Ken
http://www.ke9nr.net/
Opinions expressed are my own and do not necessarily represent the views of 
my employer or anyone in their right mind.