It depends on whether and how the receiving mail server is configured to deal
with incoming email. Note that I'm assuming the problem is people with (e.g.)
yahoo.com addresses receiving bounce messages when they send to contesting.com.
In the case of Yahoo.com, their servers know with certainty who is allowed to
send mail on behalf of yahoo.com. Contesting.com is definitely not on the list
of Yahoo authorized senders, so it rejects the delivery attempt and
contesting.com, in turn, bounces the email back to the sender, The issue I see
is with yahoo, or ANY email server, is what to do if it receives an email from
a server and it cannot determine whether that server is authorized to send mail
on behalf of the domain in the FROM: clause.
Spf is a good example of how this scheme is supposed to work and also
illustrates the rather mediocre results (filtering out spam) you can expect
without universal adoption. For the uninitiated: DNS (domain name service) is a
directory program that translates names to IP addresses. For example,
www.hourglass.com (picking a simple example - sites like Yahoo are more
complicated because they will have several servers that can service requests
for www.yahoo.com) translates to 209.157.71.217. How the directory works for
your browser is that your computer queries a DNS server specified by your ISP.
That DNS server probably says "I don't know about hourglass.com, let me find
out by asking the DNS server that hosts that domain." Eventually it finds a
server that is "authoritative" for hourglass.com and asks what the IP address s
for www and that DNS server returns 209.157.71.217. At which point, your
browser connects to 209.157.71.217 to read the webpage.
In order to send mail, your mail server looks for a special directory entry
called an mx record. The mx record tells the server asking what the IP address
is of a mail server that will process incoming mail for hourglass.com.
To help beat spammers, spf was introduced a number of years ago. This is a
record in the domain DNS server that lists all the IP addresses are allowed to
SEND email claiming to come from, say, hourglass.com. So if you want to reduce
spam, you can query the hourglass.com DNS server and find out if the email
advertising cheap Viagra actually originated from one of the servers listed in
the spf record. If not, the email can be safely rejected.
The problems arise when a domain DNS has NO spf record at all. At that point,
the receiver has no idea whether the email originates from a legitimate source.
The safe thing to do at that point is to just let the email pass through;
otherwise the false positives would cause too much email to be rejected as spf
has not been universally adopted.
Sorry for the long-winded explanation...
Al
AB2ZY
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
john@kk9a.com
Sent: Monday, April 14, 2014 8:21 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Bounces
Until I purchased my own domain, I used the arrl.net forwarder and sent emails
as kk9a@arrl.net. It is easy to do with Outlook, Outlook Express, gmail and
many other programs. I am not sure that using a forwarder will solve all of the
bounce problems.
John KK9A
To: towertalk reflector <TowerTalk@contesting.com>
Subject: Re: [TowerTalk] Bounces
From: Mike Reublin NF4L <nf4l@comcast.net>
Date: Mon, 14 Apr 2014 16:24:37 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Thanks for the info Gary. I'm a Comcast user, and I got un-subscribed.
I don't think it's possible to use a remailer such as ARRL or pobox because the
"FROM" header is still going to be your real email provider. If you know how to
do it, please post instructions.
73, Mike NF4L
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