Email security features impacting your newsletter open rate

Are your email newsletter open rates low, but you don’t know why? 

SPF, DKIM, and DMARC are all three security protocols that can and should be installed on a domain that indicate to an email provider (i.e., Gmail, Yahoo, Outlook) any time they receive an email from that domain: Hey, we’re all good here!

In 2024, Gmail and Yahoo actually began requiring DMARC to get through a spam filter, even if the recipient tried to mark it as “not spam.” Outlook/Microsoft followed suit in 2025. 

Here is what each one means and how to know which one is impacting your open rate.

‍*Note: If you use Substack or Beehiiv to send your email newsletter, this does not apply to you.

What’s DKIM & SPF? 

SPF and DKIM are more basic security measures to protect people from spam and to protect senders from being spoofed. 

They are similar, but different. 

‍SPF record -> added directly to your domain’s DNS settings.

DKIM record -> also added to your DNS settings, and you generate it through your ESP (i.e. Mailchimp)

What’s DMARC?

DMARC tells receiving mail servers what to do when SPF and/or DKIM checks fail, and optionally sends you reports about those failures.

This is an added layer of security and has become increasingly important since 2024. Yahoo, Gmail, and Outlook will block emails that do not have a basic DMARC record set up.

‍How to fix it

First, you will want to check your domain records to see if these three security features are installed correctly. 

1. Head on over to http://mxtoolbox.com/dmarc.aspx
2. Type in your website domain (do not include www.)

Because every domain is different and requires different processes to fix an issue, If you find that one or more of these protocols are missing from your domain, our team is prepared to help you. 

Please email your flytedesk account manager to set up a meeting or to receive an email with your specific instructions to properly fix the issue. 

What if all three are installed correctly? 

If all three protocols are installed correctly, there may be other reasons as to why your open rate is low. 

Read our guide on optimizing your newsletter engagement rates.

What’s next

One of our favorite topics here on the flytedesk Publisher Team is email newsletters! We are prepared to help you with a variety of newsletter needs, like subscriber list growth, newsletter content, newsletter advertising, and more. 

Reach out to your account manager for newsletter guidance at any time.