Comments on: FreshBooks now supports SPF

By: Henning Geiler

Henning Geiler — Sat, 04 Oct 2008 14:26:08 +0000

Hello Kevin and Scott. Thank you very much for your help. I did as per Scott’s suggestion, ran a 3rd party validation tool, and it seems to be working very well.

By: Scott Girard

Scott Girard — Wed, 01 Oct 2008 03:38:35 +0000

Here’s another helpful page that discusses using multiple include: mechanisms.

http://www.schlitt.net/spf/spf_classic/draft-schlitt-spf-classic-02.html#mech-include

By: Scott Girard

Scott Girard — Wed, 01 Oct 2008 03:23:27 +0000

Um, I think Henning’s record should look like this:

v=spf1 include:72smtp.whatever.com include:_spf.freshbooks.com ~all

The ~all should go at the end of the record and multiple include: statements are valid.

See here:
http://old.openspf.org/mechanisms.html and here:
http://www.spamresource.com/2006/09/sender-policy-framework-spf-trick-of.html and here:
http://www.kitterman.com/spf/validate.html

By: Kevin

Kevin — Tue, 30 Sep 2008 15:56:23 +0000

Hi Henning,

You can add the snippet Rich provided to the end of your existing txt record. So, if your current record said:

v=spf1 include72smtp.whatever.com ~all

You should update it to say:

v=spf1 include72smtp.whatever.com ~all include:_spf.freshbooks.com

Below is a link to the documentation from the SPF project, which explains what each of these directives means.

http://www.openspf.org/SPF_Record_Syntax

By: Henning Geiler

Henning Geiler — Tue, 30 Sep 2008 03:24:14 +0000

I don’t understand the working of this. How is the DNS record supposed to look like. I have set up SPF records for two other external mail servers and in both instances I was instructed to create DNS record or the type TXT and then add the following line: v=spf1 include72smtp.whatever.com ~all. How does this go together with the snippet of code you posted in your blog? Would it be possible to create the TXT record and then add the following for freshbooks.com?
v=spf1 include72spf.freshbooks.com ~all

By: Rich Lafferty

Rich Lafferty — Sun, 14 Sep 2008 17:03:39 +0000

Fixed, thanks!

By: bri

bri — Sun, 14 Sep 2008 06:04:40 +0000

It’s “sender policy framework”.

By: Joe

Joe — Wed, 10 Sep 2008 05:14:06 +0000

Good info to know! I appreciate the extra effort to explain it, rather than just “yes that’s correct”.

By: Rich Lafferty

Rich Lafferty — Wed, 10 Sep 2008 02:18:39 +0000

Joe: Yep! That’s the standard for “this DNS record only exists as an SPF record for other domains to include”.

The underscore prevents the possibility of colliding with a hostname (since hostnames can’t contain underscores). That’s why they’re used in SRV records, too.

By: Joe

Joe — Wed, 10 Sep 2008 02:07:00 +0000

Just wanted to make sure that the underscrore in _spf was supposed to be there.