We have been told that we need to set up a Reverse DNS for our
domain names so they aren't rejected by AOL or Yahoo.
having a PTR is absolutely required for a business mail server, and
good policy to enforce with outright rejection (like aol and yahoo)
or heavy negative scoring.
The best practice is very simple:
1. d.c.b.a.in-addr.arpa PTR label.domain.tld.
AND where there is a matching A record:
2. label.domain.tld. A a.b.c.d.
Each of our domains are set up on a virtual IP and not tied to one
IP address for each domain name. Is it possible to set up a reverse
dns or PTR record for Each domain or can we only do one for the
main IP address? All of this is foreign to me but a real problem
with our users.
This is the message we get from
Thank you for contacting Online Support.
The sender's IP (64.7.207.173) has been blocked due to a bogus helo.
helo is not a DNS or reverse/PTR question. "HELO/EHLO domain" is
given by mail server when sending, and Imail takes care of this automatically.
Bogus helo indicates that a system provided a falsified IP
spammers very often say HELO with the MX's IP address or with their
IP address. While any IP address in HELO is illegit, except when
domain literal with the brackets notation of [ip.ad.re.ss]. A good
policy is to reject any sender that says
HEL0 ip.ad.re.ss
no matter what the IP is.
or name
The EHLO/HELO domain name must be valid DNS domain name that has at
least an A record. There no need to make the PTR and HELO domain
names the same, although that won't hurt, and will probably help your scoring.
Len
