IIS and SMTP - How to setup smarthost with ISP smtp and authentication

Author

How to setup smarthost with ISP smtp and authentication

Victor

2004-10-15, 9:25 pm

My ISP is Adelphia using a cable modem. They allow email software, such as
outlook, to handle email by using the address mail.adelphia.net. I believe
they require authentication for outgoing mail, but am not sure. What I need
to know is how to setup IIS to use mail.adelphia.net as a smarthost,
including setting up authentication to the smarthost. I tried just throwing
mail.adelphia.net into the smarthost section under delivery, but my messages
were just thrown into the queue.

OS: Windows 2000 Server
Web Server: IIS 5
I am behind a linksys router, with port 25 forwarded to the smtp server I am
working with.
ntlookup -type=mx hotmail.com shows me valid dns info.

Any help is appreciated, thank you in advanced! These forums have been a
great help to me.

Jeff Cochran

2004-10-15, 9:25 pm

On Tue, 12 Oct 2004 23:19:01 -0700, Victor
<Victor@discussions.microsoft.com> wrote:

>My ISP is Adelphia using a cable modem. They allow email software, such as
>outlook, to handle email by using the address mail.adelphia.net. I believe
>they require authentication for outgoing mail, but am not sure. What I need
>to know is how to setup IIS to use mail.adelphia.net as a smarthost,
>including setting up authentication to the smarthost. I tried just throwing
>mail.adelphia.net into the smarthost section under delivery, but my messages
>were just thrown into the queue.

That's to be expected. There's a difference between using a SMTP
client to access their SMTP server and relaying mail through their
server. Adelphia would need to alloow you to use them as a smarthost.
Most broadband providers don't, at least on normal household
connections, but you can ask them to be sure.

On the other hand, you may be able to send SMTP mail fine without
using a smarthost. Provided your ISP doesn't block port 25 (many do
because of the trojans which bounce spam through compromised systems),
you can use your own SMTP server to send mail. Though you will likely
run into problems with receiving systems not liking your system on a
dynamic IP with no valid reverse DNS.

Jeff

>OS: Windows 2000 Server
>Web Server: IIS 5
>I am behind a linksys router, with port 25 forwarded to the smtp server I am
>working with.
>ntlookup -type=mx hotmail.com shows me valid dns info.
>
>Any help is appreciated, thank you in advanced! These forums have been a
>great help to me.

Victor

2004-10-15, 9:25 pm

Thank you for your response Jeff!

How can I test if port 25 is blocked? Is there a way to test if they have
smarthosting enabled? If there is a way for me to find out on my own, I'd
rather do that to avoid bringing to their attention that I want to run a
small webserver. Otherwise, I'll ask them as a last resort.

Also, is there a way for me to test if my SMTP is capable of sending out
mail without getting rejected? If it is rejected, how can I tell? If my
SMTP server is unable to send out on its own, are there free smarthosts
available on the internet?

"Jeff Cochran" wrote:

> That's to be expected. There's a difference between using a SMTP
> client to access their SMTP server and relaying mail through their
> server. Adelphia would need to alloow you to use them as a smarthost.
> Most broadband providers don't, at least on normal household
> connections, but you can ask them to be sure.
>
> On the other hand, you may be able to send SMTP mail fine without
> using a smarthost. Provided your ISP doesn't block port 25 (many do
> because of the trojans which bounce spam through compromised systems),
> you can use your own SMTP server to send mail. Though you will likely
> run into problems with receiving systems not liking your system on a
> dynamic IP with no valid reverse DNS.
>
> Jeff

Jeff Cochran

2004-10-15, 9:25 pm

On Wed, 13 Oct 2004 11:01:03 -0700, Victor
<Victor@discussions.microsoft.com> wrote:

>Thank you for your response Jeff!
>
>How can I test if port 25 is blocked? Is there a way to test if they have
>smarthosting enabled? If there is a way for me to find out on my own, I'd
>rather do that to avoid bringing to their attention that I want to run a
>small webserver. Otherwise, I'll ask them as a last resort.

A telnet to port 25 may give an indication, but most likely they don't
relay.

>Also, is there a way for me to test if my SMTP is capable of sending out
>mail without getting rejected?

Send mail, see if it gets there.

> If it is rejected, how can I tell?

You should get a NDR response and see it in the SMTP log files.

>If my
>SMTP server is unable to send out on its own, are there free smarthosts
>available on the internet?

Not that I know of. Why would someone freely let you relay mail
through them, risking you being a spammer or compromised by a spammer,
at the risk of losing their own connectivity?

Jeff
[vbcol=seagreen]
>"Jeff Cochran" wrote:
>

Victor

2004-10-15, 9:25 pm

Thanks again for all your help Jeff.

I can indeed telnet to mail.adelphia.net on port 25. I was wondering if it
was possible to input commands after telnetting to the mail server to test
relaying. Such as the RCTP command, if relaying is enabled then that should
work, while if relaying is prohibited it should be rejected, right? I do
realize it could be more complicated than that, but this is my guess.

As of right now, it appears mail can be sent out! I have mail.adelphia.net
setup as the smart host, but also have "attempt direct delivery before
sending to smart host" checked, so I figure it is directly delivering the
mail, although I am going to test this later to make sure. None-the-less, I
have successfully had mail delivered to my hotmail account. I reset the FQDN
from mydomainname.com back to <mymachinename>, which I had changed for
testing purposes, and I rebooted the computer, so I'm assuming it was one of
both of these things that helped fix the problem.

Thanks again for your help Jeff, wouldn't be anywhere with you and everyone
else here on the community discussion boards!