How to combine Google Apps SPF & Campaign Monitor SPF?

Question

I'm trying to combine two SPFs into one, namely a Google Apps and Campaign Monitor SPF.

Is there any possible way to do this?

E.g.

SPF A:
v=spf1 include:_spf.google.com ~all

SPF B:
v=spf1 mx include:cmail1.com ~all

What is A + B ?

Answer 1

Let's break it down:

v=spf1

Just says the version of SPF being used and that this is an SPF record.

include:_spf.google.com

Parse the SPF rules on _spf.google.com (i.e. if the source would pass against _spf.google.com, then it will pass against your site)

~all

Soft fail if none of these rules are matched (-all would be a hard fail, which people generally avoid when setting up Google Mail on their domain)

mx

Allow the source IP to send as the domain in question if the source IP is present as an MX record on the domain.

include:cmail1.com

Another include, this time against cmail1.com

Final result:

v=spf1 mx include:_spf.google.com include:cmail1.com ~all

I used the SPF syntax page to put this all together.