It's from the OpenSPF Sender ID Framework. http://new.openspf.org/SPF_Record_Syntax explains what it does and why you need it. It basically describes your server to others and what it is responsible for etc. Microsoft use it for their anti-phising technology in IE7 I do believe.
The RDNS will help with troublesome ISPs (AOL for one) who reject any email that doesn't come from what they consider a valid mail server, which I gather is mostly one with an IP address that doesn't resolve back to the hostname where the email originated from.
As for the MX record possibly being wrong, I have the following set up for here and it works fine:
code:
tehforum.co.uk. NS ns1.tehforum.co.uk.
tehforum.co.uk. NS ns2.tehforum.co.uk.
ns1.tehforum.co.uk. A 83.149.123.55
ns2.tehforum.co.uk. A 83.149.123.57
tehforum.co.uk. A 83.149.123.55
ftp.tehforum.co.uk. A 83.149.123.55
mail.tehforum.co.uk. A 83.149.123.55
www.tehforum.co.uk. CNAME tehforum.co.uk.
tehforum.co.uk. MX (0) mail.tehforum.co.uk.
83.149.123.55 / 24 PTR tehforum.co.uk.
tehforum.co.uk. TXT "v=spf1 a mx ptr"
Technically at least one of the name servers should be hosted elsewhere so that if one of them goes down the site is still accessible but that is too much like hard work for me.
If you only have 1 IP address (we have 3) you can stick both your name servers on the same IP or manage with just the one, but whatever you call them make sure that where ever the domain is hosted it uses the same nameserver hostnames otherwise things won't work.
|
