SlerpCRM Email Authentication and Delivery

A guide to managing SPF, DKIM, and DMARC.

Upcoming changes from email providers mean that SPF, DKIM, DMARC and Bounce records must be setup for anyone sending bulk emails from the 1st of February 2024. If you have not set this up by that date, you will not be able to send emails, so it's important to get this setup as soon as possible.

DMARC, DKIM and SPF are used to authenticate email addresses to help prevent spammers, phishers and other parties from sending emails on behalf of a domain that they shouldn't have access to.

SPF specifies which mail servers are authorized to send emails on behalf of your domain, preventing spammers from impersonating your domain.

DKIM adds a layer of security by digitally signing your emails, verifying their authenticity and integrity. Both SPF and DKIM contribute to your emails being trusted by email service providers and recipients, reducing the chances of them being flagged as spam.

DMARC allows domain owners to specify how email receivers should handle emails that fail SPF and DKIM checks. It enables the domain owner to set policies that determine whether to reject, quarantine, or allow emails that don't pass authentication.

The TX(Analytics) record updates ensures that the analytics collection (including tracking clicks and opens) within the email campaign utilizes your domain rather than the generic

The BOUNCE update is used for all bounce notification emails. It is commonly known as the "envelope sender".

How to setup SPF, DKIM, DMARC and Bounce on your domain

  1. Please request the SPF, DKIM, DMARC, and Bounce details for your SlerpCRM from the Slerp support team (
  2. The data will be provided to you in a table via email, similar to the below, containing the required details of the DNS records that need to be created. 

  3. You will need to add new records to your DNS settings with the portal of your domain registrar (eg: GoDaddy). We recommend that you provide your IT team with the details above in order to make these updates or reach out to the support team of your domain registrar so they can provide you with instructions.
  4. You will need to ensure you have a record for the following
    SPF - You can only have one SPF record per domain. If you already have an SPF record setup, your IT team or domain registrar will need to edit the existing one
    TX - This is not required, but is helpful for delivery and should only take a couple of seconds to add so we highly recommend settings this up.
  5. Once the updates have been made, please reply to the email you received with the SPF/DKIM details in it, informing us that the records have been added. We will then test that they are functioning correctly, and confirm that everything is working correctly.