I’m feeling lost in DNS; please help me get back on track.
- I’ve got a domain. Let’s call it
example.com. And I can add DNS entries for subdomains of type A and CNAME.
- I have another server which I want to be available as
foo.example.com. And I’ve got a mail server there.
When I send emails to certain servers from
foo.example.com they get rejected as spam, based on the absence of a PTR record. So, the first question is, What can I do to fix this?
Right now I only have an A record at the DNS of the registrar of
I can add all kind of DNS entries for
foo.example.com using name servers of another provider. Right now there no such entries.
And the second question is, Can I pull this off without downtime?