setting up a local outbound mailserver at home for dialup

[Joseph Moran]

On Thu, 20 Nov 2003, Joseph Mack NA3T wrote:

> if I use
>
> $ mail
>
> and send something by hand, I get the reverse DNS error at the target
> machine, meaning that it bypassed the ISPs username/passwd step.

Interesting.  Most stock implementations of 'mail' have no idea about
using another MTA as a relay, they just attempt a direct TCP connection to
port 25 of the host that claims to receive your recipient's mail.  In this
situation, it sounds like 'mail' succeeds in the connection (so your new
ISP isn't blocking outbound sessions to port 25), but the recieving host
is telling your 'mail' to piss off because your (public/external) IP
address doesn't resolve.  Many ISPs provide reverse DNS for their PPP
address pools, but many don't.  I guess yours doesn't.  You could always
try pointing out this deficiency to them -- it's not hard to fix if they
put their minds to it.

You're able to send mail out by relaying through your ISP's MTA.  That's
probably what your ISP would prefer you do.  Are you able to send mail in
this manner -before- you run into this HTTP login window?  You'll probably
have to use a non-Web mail client to test this.  Pine is easy enough to
use for this sort of testing, and it can be told to use an SMTP gateway.

Setting up an SMTP server on your own gateway won't get around the reverse
DNS issue on its own.  You could do it provided you had your SMTP server
relay through your ISP's MTA (if you do this, you'll need to tell your
mail client to use your own SMTP server as the MTA instead of your ISP's).
I'm not sure the added complexity is warranted here.

Kind of funny that your IP address doesn't resolve, but your ISP's MTA
accepts mail from it.  I wonder if it performs the reverse DNS test at
all, or just skips it for the PPP pool.

-jrm