Mimecast SPF Setup

SPF (Sender Policy Framework) is an email authentication method that allows domain owners to specify which mail servers are authorized to send emails on behalf of their domain. This helps reduce the risk of spoofing and ensures legitimate emails are correctly delivered.

This guide provides step-by-step instructions for setting up SPF with Mimecast, a cloud-based email security and management provider.  

Mimecast SPF Requirements

Mimecast has multiple SPF record includes for the many different regions where they have data centres housing your Mimecast instance.

Please add the relevant includes for the region of your Mimecast instance.

Global Includes

This is not recommended as it will add the SPF includes for every Mimecast Region which adds a total of 5 lookups to your SPF record.

Note: If you’re already using Sendmarc for SPF management, simply copy your regions’ include and follow the steps here.

To authorize Mimecast to send emails on your domain’s behalf:

1. Log in to your domain’s DNS dashboard.
2. Go to the page where you can update the DNS settings on that domain.
3. Check if a TXT record starting with v=spf1 already exists.

• • If it exists, modify the existing record to include Mimecast (details in the table below – using the ZA region as an example).
  • If not, create a new TXT record.

Example of an updated SPF record:

Example of a new SPF record:

4. Save your changes in the DNS control panel.

Allow up to 48 hours for DNS propagation, depending on your DNS host.