Assistance with SPF Records for BIND

[Jonathan Vomacka]

BIND Community Support,

I am inquiring about how to setup a proper SPF record? I know there are 
SPF wizards/generators available but each seem to have a different 
"opinion" of what should be included and what should not be included.

Let me give you a scenario of my setup, and hopefully someone can help 
me out.

My domain is: test.com
My mailserver hostname is: mail.host.com which also has a MATCHING PTR 
record
mail.host.com (for example) resolves to 50.1.1.1 and 50.1.1.1 resolves 
to mail.host.com

This is a STANDALONE mail server without any VIP's or load balancing. 
There is however one additional host that will send out mail from the 
domain but it wont be receiving mail, it will only be used as an SMTP 
server attached to a website automailer... It only generates error 
reports and sends them out... so technically it isn't a full mail server 
but it will be sending (outbound only) mail on behalf of the domain.

The additional host is: mail2.test.com which resolves to 50.2.2.2 and 
there is a Matching PTR.

These are the ONLY mail servers and IP addresses that will be sending 
out mail from the test.com domain. Some websites say I should use -all 
and others say -all will cause some MTA's to reject and ~all is better 
to use even if those are the only two hosts sending out mail.

Would you be able to assist with a solid SPF record?