Domain Setup Guide - New Domain/Sub-Domain

This guide is intended for setting up a domain that is going to be fully dedicated with CommuniGator.  It is not a domain being used for other purposes, such as your main company domain.  

Do not follow the steps in this guide without understanding what your sending domain means.  Please read the introduction first here Domain Setup Guide - Business Domain vs New Domain: Which one should I use?

Creating a new domain/sub-domain is very similar to setting up your main company business domain, apart from a few small changes.

Your sending domain is an important business asset so you should own and control it, hence why we do not set them up for you (this is normally done by your IT Team or Web Developer).

Please follow the sections below to configure the domain:

Choose your New Domain

The domain you setup will be dedicated to your email marketing, so make sure  you choose an appropriate domain name. Remember this domain is what recipients will see as the sender email address and links in the email content so brand recognition is key.  If you need to purchase a domain you can do so from a multitude of sites including Google, Wordpress etc. If you have not done so already please read the introduction first here Domain Setup Guide - Business Domain vs New Domain: Which one should I use?


Create your Domain Keys

Domain keys are essential to your setup as they are used to verify the domain name of an email sender, as well as the message integrity. The DKIM record tells a recipients mailbox that you own the message and it is authentic. This is key in ensuring your emails are received.

If your company domain already has DKIM authentication for another purpose, you simply need to setup a new DKIM with a different "keyname", for CommuniGator DKIM authentication to work.

1. SparkPost is the DKIM wizard we recommend for generating your keys. Head to the following URL for access:

Generate a private & public key pair by filling in:

1. Domain Name e.g. ""

2. Domain Key Selector as 'key1'.

3. Select the relevant key size. This provides a level of encryption for your domain key. The larger the key size, the greater the level of encryption.

4. Select "Create Keys".

Please Note: some domain providers may not support 2048 bit encrypted keys, so if you are unsure use 1024 bit keys.

Upon clicking "Create Keys", the keys will be generated below. You will see a public and private key.

5. Copy the text from  “-----BEGIN PUBLIC KEY------” to “------END RSA PRIVATE KEY------". Put this into a text file and save it as "[Domain Name]_keys.txt"

6. Copy the text indicated above, making sure you copy everything from between the quote marks. Save this in a separate text file.

It is crucial that the format of the key you have copied is exactly the same as the one in SparkPost, otherwise the authentication will fail.

Configure your DNS Records

You MUST apply the following settings to the DNS management of your domain. These changes will normally be made by your IT department if you self-manage your domain or use a third-party domain provider with a managed domain.

The DNS settings to configure for your new domain are:

Record Answer
MX (Priority 1)
v=spf1 -all
_dmarc (DMARC TXT)
v=DMARC1; p=quarantine; sp=quarantine; rf=afrf; pct=100;
key1._domainkey (DKIM TXT)
Your Key Selector from the Port25 DKIM wizard e.g. k=rsa; p={key}

PLEASE NOTE: Port25 adds slashes in front of the Key1 selector e.g. k=\\rsa;. You MUST remove the slashes or the record will fail authentication.

You can find your key selector in the text file you saved from Port25, as shown in step 6 of 'Creating Your Domain'.

Checking your DNS is set up correctly...


Here is a checklist of items to compare against your DNS. These must be checked and point to the correct location or your domain reputation could be impacted.

  • Your DNS MUST have A, MX, and TXT records.
  • Your A record must have an answer of
  • Your MX record must have an answer of
  • Your SPF TXT record must have an answer of v=spf1 -all.
  • Your DMARC TXT record must have an answer of v=DMARC1; p=quarantine; sp=quarantine; rf=afrf; pct=100;
  • Your DKIM TXT record must exist. it will start with "k=rsa; p={key}" and within {key} will be a string of numbers and letters. This will vary from each domain.


If you have problems with your DNS authenticating it is likely the records are not set up, or are not pointing to the correct location. Please re-visit the steps above to check your records.

Contact Support

Email CommuniGator Support on, and provide us with the domain name and the text file from Port25, during domain set up.

We will check the domain is setup correctly and test the different authentications.  If everything is correct, we will add the domain into your instance making it available immediately for use.

Please Note: If you are unsure of the steps outlined in this guide, please speak to your IT department or, for help and advice, do not hesitate to contact