Configure Trade E-Mail Server Reverse DNS and MX Information Correctly
If DNS is set up incorrectly, about time your mail server IP will be included to blacklists. These days most E-Mail servers have some form of spam safety assistance which in flip indicates that all your inbound mail will be blocked if you do take place to be outlined on a spam blacklist.
In this report I will describe how to the right way configure your MX and reverse DNS records for your mail server. This report is dependent on an Exchange 2003/2007 server but each and every other messaging server will stick to the very same theory.
Assigning an IP handle
Setting up from the base up the first point you want to do is assign a static exterior IP handle to the inner non-public tackle of your mail server. You will require to use these rules on your firewall to port forward SMTP (port twenty five) and NAT an exterior IP handle to the internal deal with of the server.
Anything that a whole lot of administrators forget about to do or test is to established the outgoing NAT rule to use the similar exterior IP address created for the inbound rule to the mail server. If this is not established, Reverse DNS will not match and in switch your mail server will be outlined on blacklists. If your firewall policies are set up properly the IP handle mentioned on this page really should be the very same IP address you mapped to the inner non-public IP tackle of the mail server.
Build the MX information for your mail server
For the reason of this example, stated underneath are all the information of my mail server to enable you fully grasp what you need to have to do.
External IP: 184.108.40.206
E-Mail Domain: area.com
You will need to have to be an administrative get in touch with for your Exterior DNS company for your area to make these changes. In most instances this can be carried out by way of an on-line management panel by way of your DNS supplier. Failing that on the cellular phone or by means of E-Mail.
one. The to start with thing we require to do is create an A history to point to the exterior IP tackle mapped on your firewall to the mail server. The host A record can be identified as any detail but is commonly called «mail». In our case in point we will generate «mail.area.com» to level to IP deal with «220.127.116.11»
two. Upcoming we will develop an MX record to point to the freshly developed A file of our mail server.
Within just your DNS command panel select «add MX history». Make confident that the host handle is the root area name in our scenario «domain.com»
Established the FQDN as the A document we just established which in our circumstance is «mail.domain.com».
The least expensive property is the most desired but in our case in point we will set the precedence as ten.
Use NSlookup to check out DNS and MX records are utilized
It can take up to forty eight hours for DNS to propagate but in most instances 12-24 several hours. To verify our DNS entries are utilized and accurate we can use nslookup.
1. Open a CMD prompt and kind nslookup
2. Sort established sort=mx
3. Form the domain title which in our situation is domain.com.
In our case in point the output must examine as follows if correctly set up:
domain.com MX preference = 10, mail exchanger = mail.domain.com
mail.domain.com internet deal with = 87. Should you loved this informative article and you want to receive more details concerning smtp service i implore you to visit our own web-page. 22.1.22
Configure Reverse DNS
Reverse DNS is made use of to validate that the mail server is who it suggests it is. The recipients mail server will do a reverse lookup to make certain that the IP deal with of the mail A or host document in DNS is the similar as the IP address it is speaking with. Only one RDNS entry can be present for each IP address.