Is Reverse DNS important for email?
There are many security measures that your domain needs to pass in order for your emails to reach your clients’ inboxes. Reverse DNS is the biggest deliverability killer, as almost all mail servers use this method to verify incoming domains.
What is Reverse DNS used for?
Reverse DNS (rDNS or RDNS) is a Domain Name Service (DNS) lookup of a domain name from an IP address. A regular DNS request would resolve an IP address given a domain name; hence the name “reverse.” A special PTR-record type is used to store reverse DNS entries.
Which DNS records are commonly used to stop email spoofing and spam?
One common function is to use the TXT record to create a Sender Policy Framework (SPF) record. SPF records stop email spammers from forging the From fields in an email, which allows the owner of a domain to designate the IP address that can be used to send email from that domain.
How does reverse DNS work for mail servers?
When a mail server receives a request from your domain’s mail servers, it will take the IP provided (of your mail server) and do a reverse DNS lookup to see if that IP’s zone points back to your domain. Now we are going to create a special kind of record is only used by other mail servers that receive mail from your domain.
What happens if you don’t have a reverse DNS record?
As the name states, these records do the reverse of what a normal DNS A record does — they map IP addresses back into host names. Without a valid reverse DNS record, many ISPs will block your email . Here’s a simple example showing a forward, conventional DNS lookup using an A record and a reverse DNS record. Here’s another example from Microsoft:
How are PTR records used in reverse DNS lookups?
Now we need to create a record that points our mail server back to our domain. This record is called a PTR record. PTR records are used in reverse DNS lookups which are conducted by mail servers to make sure that the other mail server they are dealing with is who they say they are.
What kind of DNS record do I need to send email?
These are the 3 DNS records you must have correct for sending email reliably. Of course, you need an MX record if you want to receive email, but that’s another topic. If you have to get one DNS record right, the reverse DNS record, also know as a PTR record, is the one.