Re: how to deal with ptr records and getting classified as spam under the http://workaround.org/articles/ispmail-etch/ -config

[Mike Bird <mgb-debian@yosemite.net>]

On Fri October 10 2008 23:36:55 blorb wrote:
> you can only have one PTR per IP
> try asking your ISP for more address (it cost some money)
> or set the MX record into one "mail gateway"

You CAN have more than one PTR per IP.  See e.g. last
para of section 3.3 of this IETF draft:

http://tools.ietf.org/html/draft-ietf-dnsop-reverse-mapping-considerations-06

For example:

$ host 12.234.40.252
252.40.234.12.in-addr.arpa domain name pointer mx1.yosemite.net.
252.40.234.12.in-addr.arpa domain name pointer mariposa.ca.us.
252.40.234.12.in-addr.arpa domain name pointer yosemite.net.
252.40.234.12.in-addr.arpa domain name pointer ims.mariposa.ca.us.
$

--Mike Bird