As no standard has been agreed upon by the industry as the method by which to accept or deny mail, senders must take care to comply with as many industry “best practices” as possible. We will detail here the most common ones and how to set them up using our services.

If your mailing fits the Spamhaus spam description, note that it is prohibited on our network and your service will be terminated without notice.

Ensure you are also in compliance with their guide laid out for email marketers. Of particular importance is to never operate lists you've not gathered yourself, and always respond promptly/appropriately to removal requests.

Using consistent From: addresses and removal procedures is always recommended. Cleaning lists of bounced recipients will help keep your list clean and reduce your processing & bandwidth requirements.

Proper Reverse DNS or rDNS records are essential to mail deliverability. If one standard has been agreed upon the most by the industry, it is the existence of matching forward and reverse DNS records. In a default setup, mail will flow out of your server via the base IP (usually eth0 or “Default Adapter”). This IP should have a forward DNS record (A record) associated with it that gives it a name. An example is below for a host named test.example.com (test for short):

test.example.com.              IN      A             1.2.3.4

This is your forward record that resolves a name to an IP. You also want a reverse record that maps your IP back to your hostname. This looks like:

4.3.2.1.in-addr.arpa.          IN      PTR           test.example.com.

To set this up using our VPS service, log into your VPS Manager and go to Configuration → Reverse DNS. For a dedicated server, please email support@ndchost.com.

SPF records are also DNS records that some receiving mail hosts use to verify the authenticity of mail. The SPF record provides a list of addresses (IPs and DNS names) that are allowed to send mail on behalf of a particular domain. Since it is a simple DNS record, SPF is relatively easy to set up.

On a cPanel server, log into the cPanel interface for the account you wish to setup SPF on, and go to Mail → Email Authentication, and enable SPF. As long as your DNS is hosted locally, nothing else is needed! If your DNS is hosted locally and mail is hosted remotely, you'll need to modify the SPF record using the wizard to add your mail host's name or IP address.

On a non-cPanel server, you'll need to first generate an appropriate SPF record. You can do so using this SPF Generator. Enter the record in your DNS server as a TXT record as specified, or email it to us if you are using our DNS servers.

Domain Keys is another type of email verification system using public key cryptography. Due to this, it is more complicated to setup than SPF and less hosts implement and check for it. If you send mail often to Yahoo addresses, it is recommeded you implement this technology.

For cPanel servers, it is as simple as enabling it on the same Email Authentication screen as SPF, provided your DNS is hosted locally.

For non-cPanel servers, the process is relatively involved to configure Domain Keys support, however below are a few resources for implementing them.

• DKIM for Sendmail
• DKIM for Exim