[quoted text, click to view] > I installed the SMTP thing in win XP but now what? Where do I dind
> anything to configure that and can I use that for sending my emails?
Do you really have "SMTP problems" with IIS SMTP? Doesn't seem like
it. It seems you don't have experience with SMTP (and thus with DNS)
in general. I know this will come off as harsh, but I daresay you
shouldn't be in charge of a mailserver that's exposed to the public
Net if you don't have those prerequisite skills.
If you restrict your new mailserver to _only_ allowing outbound
connections, though, it's true that you can do little harm to anyone
but yourself. But you are still going to need to learn quite a lot to
make sure that your self-administered mailserver is capable of
successfully delivering to the vast majority of remote servers, even
those with strict anti-spam policies.
To approach your question: the default IIS SMTP is essentially capable
of relaying mail to remote domains right out-of-the-box. You must set
up your mail client to authenticate to the SMTP server. The rest is
out of IIS' hands -- and the *rest* is in fact the most important
part.
The rest:
[1] You must ensure that your server passes the HELO-PTR-A-IP
roundtrip test. This means that
- you must have a PTR record for your mailserver's public IP address
- the HELO greeting sent by your mailserver ("FQHN of the Default SMTP
Virtual Server" in IIS terms, though this requirement applies to all
mailservers) must match the PTR ("reverse DNS") hostname of the public
IP address
- the PTR hostname must have a corresponding A record that resolves to
the public IP address
The roundtrip test is very simple, really: all published DNS and SMTP
data must be consistent. Not every remote server checks _every_
element. But any inconsistency means one more chunk of remote servers
will refuse your mail.
[2] Your ISP's routers must allow you to make outbound connections on
TCP port 25.
[3] Your ISP's EULA must allow you to send mail directly to remote
servers. It is not enough to "fool" your ISP by using a DDNS service.
That might work for inbound HTTP, but not for outbound SMTP. Even if
the ISP does not block you at the network level ([2]) from connecting
on TCP 25, many remote servers use complex and generally accurate
heuristics to determine whether you are using a consumer-grade (that
is, server-free) block of IPs. (Since spambots commonly violate EULAs,
better safe than sorry.)
[4] Self-evident: all usernames and domains you send from must exist
in the public DNS. Your submission server (IIS SMTP) will not look
this up for you. Remote servers happily will.
[5] If you are using a domain with an SPF record, your mailserver's
public IP address must appear as an explicitly allowed sending server,
or, alternately, an SPF query must return an "unknown" result for
your server.
--Sandy