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SMTP Reverse Lookup

What you see when your domain has this problem
DNS Failure During Reverse DNS Resolution Details area Ignore

More Information About Smtp Reverse Lookup

We were unable to perform a reverse IP address (PTR) lookup on your SMTP email server.  This is a problem because many organizations will not accept email from a server without a reverse record.  

We recommend performing a Reverse Lookup on the IP Address for your mail server to try to find the cause of the error.  You will probably need to contact your ISP and ask them to setup a reverse (PTR) record for you.  

You should ask that this record be the same as your forward DNS name (e.g. mail.example.com).  We also recommend configuring your server to include this name in your HELO banner.

Additional Information

When a sending server makes a connection to the recipient server, the recipient server notes the sending IP address and performs a reverse lookup. This is done by sending a DNS query which returns a Fully Qualified Domain Name ( FQDN) registered for that IP address. If the sending SMTP address matches the domain, then it's much more likely that the message is legitimate and therefore will be passed on to the recipient. If the IP address doesn't match, it's much more likely that the sending address was spoofed and therefore much more likely that it's unwanted and could be considered spam. 
A FQDN is associated to an IP with a valid PTR record. You want the domain name portion of the FQDN to match the domain of your email address. (e.g. if your sending addresses follow the convention of name@mydomain.com, your PTR record should contain something like mailserver.mydomain.com). Only the organiztion which controls and owns the IP can set a PTR record. PTR record queries are sent to the owner of the IP address which is the ISP, unlike other DNS queries which are sent to the DNS server of whoever owns the domain. For this reason Setting a PTR record on your own DNS servers is almost useless since no one is asking your servers.
To make any changes to your  reverse DNS, you will need to contact your ISP or if you host your own DNS (rare) you will adjust it yourself. You will not be able to do this in your DNS control panel unless your ISP also hosts your DNS and gives you the functionality to add your own reverse DNS records.

Are you managing your email delivery?

Email delivery is more than running an email server, or regularly checking for blacklists. To really ensure you customers get your email, you need to setup SPF, DKIM and DMARC. If you aren't manage your DMARC configuration and responses from email providers, you don't know if your customers are getting your email.

MxToolbox is YOUR expert on email deliverability. MxDelivery Center can help you setup and analyze your DMARC, DKIM and SPF to give you the insight you need to make email configuration changes and get your emails to your customer's.
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