I want to update and simplify the SPF record of my domain. Unfortunately, http://www.openspf.org/SPF_Record_Syntax is unclear.
My domain uses one MX relay for receiving and sending. The SPF rule is then as simple as this
v=spf1 mx -all. This will forbid sending mails from any other sources.
The problem I have is that one user uses it's provider (belgacom.be) for outgoing mail relay. The provider's current SPF rule is the following :
v=spf1 mx include:ispmail.spf.secure-mail.be include:bgc.spf.secure-mail.be include:bgcpartners.spf.secure-mail.be ~all
I'm tempted to define my SPF rule as
v=spf1 mx include:belgacom.be -all, but it is unclear what the
~all in the included SPF rule will do. The rules included by belgacom.be's rule also have a
~all. Will the
~all in the included rules be considered as a match and will my
-all be ignored ?
Edit: Found the testing tool http://www.kitterman.com/spf/validate.html. By adding the
include:belgacom.be I get
Permanent Error SPF Permanent Error: Too many DNS lookups. The question on the included