<Matthew(_dot_)van(_dot_)Eerde(_at_)hbinc(_dot_)com> writes:
Why do you have an SPF record for every machine in your domain? Why not
just do
v=spf1 ptr -all
Because if your domain is example.com and you have
example.com. TXT "v=spf1 ptr -all"
host.example.com. A 10.1.2.3.4
Then if mail is sent with a MAIL_FROM of host.example.com the
receiving system will perform a TXT lookup for 'host.example.com.' and
will not receive the SPF record for example.com. Therefore an SPF
record has to be published for every host which has an 'A', 'AAAA' or
MX record.