I will try to explain the context.
2 VPS with PLESK 11.5
The first (named vps67877.ovh.net - we call it v67) is a mail server (ip 37.187.33.38) The second (named vps68789.ovh.net - we call it v68) is an hosting server. (ip 92.222.8.114)
When I have a customer, I create the hosting part in v68. I create all the email adresses on v67.
For illustrate, we will take a domain we have : itbag.fr. Here is the DNS entries :
92.222.8.114 / 24 PTR itbag.fr.
blog.itbag.fr. A 92.222.8.114
ftp.itbag.fr. CNAME itbag.fr.
imap.itbag.fr. A 37.187.33.38
itbag.fr. NS sdns2.ovh.net.
itbag.fr. NS vps68789.ovh.net.
itbag.fr. A 92.222.8.114
itbag.fr. MX (10) mail.itbag.fr.
itbag.fr. TXT v=spf1 +a +mx -all
mail.itbag.fr. A 37.187.33.38
ns.itbag.fr. A 92.222.8.114
pop.itbag.fr. A 37.187.33.38
pop3.itbag.fr. A 37.187.33.38
smtp.itbag.fr. A 37.187.33.38
static.itbag.fr. A 92.222.8.114
static2.itbag.fr. A 92.222.8.114
static3.itbag.fr. A 92.222.8.114
webmail.itbag.fr. A 37.187.33.38
www.itbag.fr. CNAME itbag.fr.
I have several domains like that.
In my v67, I don't activate the DNS zone. I just say who are the servername :
114.ip-92-222-8.eu. (<= reverse DNS of v68)
sdns2.ovh.net. (<= By my provider)
Services works perfectily. But this week end, we have a spam attack... I don't know how and why, but we've got blacklisted by many DNSBL. I succeed on deleting all spams on v67, I succeed to contact all DNSBL for delist us...
When I check my configuration on MXTOOLBOX here is the report :
SMTP Reverse DNS Mismatch Warning - Reverse DNS does not match SMTP Banner
SMTP Reverse Banner Check OK - 92.222.8.114 resolves to 114.ip-92-222-8.eu
SMTP TLS OK - Supports TLS.
SMTP Connection Time 1.264 seconds - Good on Connection time
SMTP Open Relay OK - Not an open relay.
SMTP Transaction Time 3.635 seconds - Good on Transaction Time
During my communications with some DNSBL, I get a tips for one of them :
Please could you update the rDNS on this IP to be something more specific to the sender and/or your organisation rather than the generic pattern that the provider has assigned by default. You may need to contact your provider in order to accomplish this rDNS change. Continuing to send mail from an IP with a generic rDNS pattern is likely to affect your Cloudmark reputation score in the future as well as your reputation with many ISPs and DNSbls.
For instance mail.example.com would be considered far less generic than 208-83-136-1.sfo.example.com or hosted-by.example.com
But... I don't understand what they want me to do. Do I have to add a specific DNS entry like I don't know...
37.187.33.38.itbag.fr A mail.itbag.fr
I'm totaly lost...