28 February 2024

Email Deliverability 101

Configure your Mailbox to Maximise Reach and Impact


Despite the rapid growth of alternative tools and platforms, email remains a key communication channel for individuals and businesses alike with over 347 billion emails sent each day. Alarmingly, almost 15% of these emails are lost or blocked by SPAM filters. Whether you are sharing important updates with clients, collaborating with colleagues, or nurturing prospects, its critical for business continuity and growth that your emails don’t become a statistic. There are a few hygiene factors that every business should take into consideration to ensure their emails are delivered.

In this guide, we'll demystify the technical trio of DMARC, DKIM, and SPF – the foundation of email authentication for deliverability. We’ll explore some key email statistics (in case you were in any doubt about the relevance and impact of the channel), and we’ll provide some tips and tricks to move beyond deliverability metrics towards open- and click through rate.

With SYNAQ as your partner in email configuration, authentication and security, you'll not only navigate the complex world of email deliverability with ease but also ensure your messages are always met with open arms (and inboxes).

Key Email Statistics

Email is ubiquitous, an almost universal communication channel shared by more than half the world’s population. It offers practically instantaneous and auditable communication and information sharing that transcends boundaries and borders, making it the ideal platform to share updates, invoices, meeting requests and queries.

There is no area of business not impacted by email. Whether clients, suppliers, staff or prospects, email remains the primary means of sharing and receiving updates and information for most businesses. In case you were in any doubt, consider the following statistics:

  • There are 4 billion daily email users, a number expected to climb to 4.6 billion by 2025.
  • More than 347 billion emails are sent and received each day.
  • Email is the most widely used tool for internal communication with colleagues, surpassing online chat and project management tools, as well as telephone and face-to-face communication.
  • 64% of small businesses use email to reach customers.
  • 87% of brands say that email marketing is very critical to business success and email ROI stands at an impressive 36:1.
  • 38% of brands are increasing their email budget.
  • 14.3% of all emails go missing or are blocked by popular SPAM filters.

Whether sharing invoices with clients, updates with employees, or nurturing leads, how do you ensure that your emails are successfully delivered?

Ensuring Your Emails Reach Their Destination: A Guide to DMARC, DKIM, and SPF

DMARC, DKIM, and SPF are three global standards crucial for authenticating emails to reduce SPAM and email threats, and to ensure legitimate emails reach their intended inboxes safely and securely.

SPF (Sender Policy Framework): Your Email's First Line of Defence

SPF is a protocol that helps servers verify that an email claiming to come from a specific domain is authorised by the owner of that domain. Like a bouncer at the door of a club, SPF verifies emails against ‘guest list’. If an email is sent from a server not listed in the domain's SPF record, it's more likely to be rejected or marked as SPAM. Implementing SPF for your domain prevents spammers from masquerading as you, reducing risk and enhancing your email's credibility and deliverability.

View SPF infographic

DKIM (DomainKeys Identified Mail): Securing Your Email's Identity

DKIM adds a digital signature to each email, which can be verified by the recipient's server using a public key published in the sender's DNS records. Think of it as sealing your email with a tamper-evident sticker. If the sticker is intact upon arrival, the recipient knows the email hasn't been altered in transit and truly comes from you. This verification process adds a layer of security and trust, ensuring your email's authenticity.

View DKIM infographic

DMARC (Domain-based Message Authentication, Reporting, and Conformance): The Strategy Behind Email Authentication

DMARC builds upon SPF and DKIM, providing instructions to the recipient's server on what to do if an email fails these authentication checks. It's akin to leaving detailed instructions for handling your precious cargo. DMARC also includes reporting capabilities, so you'll know if someone is trying to impersonate your domain. By specifying a DMARC policy, you gain control over your email's security posture, reducing the risk of phishing attacks and improving deliverability.

View DMARC infographic

Why Email Authentication Matters

Email authentication protocols like DMARC, DKIM, and SPF are not just technical requirements for responsible digital citizenship (although they are); they are essential tools in building trust and credibility with recipients. They ensure that your emails are seen as legitimate and safe at a systems level, which is particularly important in an era where phishing and SPAM are rampant, and filters, ever more rigorous. By implementing these protocols, you protect your domain's reputation, enhance email deliverability, and secure your communications.

To illustrate the importance of these protocols, Google and Yahoo!’s 2024 Email Policy updates, effective February 2024, require that SPF, DKIM, and DMARC are in place for all bulk senders. If not, deliverability will be affected.

As these standards are so fundamental, you would be forgiven for taking them for granted and assuming that they are in place when your mailbox or mail server is configured. This is however not always the case, and you should ask your providers for assurances and proof of configuration. With Securemail from SYNAQ, these protocols are mandated, to ensure best practice is followed by implementers. If your delivery rate is lower than industry benchmarks, this could indicate that your authentication configuration needs attention.

Beyond Deliverability: Tips to Improve Open Rate and Click Through Rate

Having the basics in place to optimise delivery rate lays a solid foundation to ensure your emails make it out of the starting gate and to their destination. Once safely in a recipient’s mailbox, there are a number of tactics and best practices that you can use to maximise email open rate and click through rate. This is especially important for organisations that require bulk email functionality when communicating to their client base(s).

Firstly, what is ‘Open Rate’ and ‘Click Through Rate’?

Open rate is the percentage of subscribers who opened your email out of the total number of recipients. Click Through Rate (CTR) is the percentage of recipients who clicked on a link in your email out of the total number of subscribers who opened the email. Monitoring your open rate will give you an indication of how effective, relevant, and enticing your subject line and preview text is, while CTR will give you insight into the efficacy and relevance of your email message and value proposition.

While this will require some assumptions and AB testing, there are a number of basic principles that you can apply:

  1. The hygiene factor – clean your data!
    Sending emails to a vast data set of stale and defunct email addresses will negatively impact open and click through rates, which will skew your data and insights for optimisation. Worse, it will impact your delivery rate and, in turn, undermine domain authority.
  2. Keep it short and sweet
    Keep your emails short and to the point. Be explicit and concise in your value proposition. Remember subscribers have limited time and short attention spans in which your message must fit if it is to land!
  3. Call to Action (CTA)
    Be clear, concise and compelling as you tell subscribers what you want them to do. Call them to action with a button or hyperlink that cannot be misinterpreted.
  4. Segment and personalise
    There is no one size fits all, but some sizes fit many. Segment your audience by industry, job title or interests, and tailor messaging accordingly.
  5. Make Multimedia mobile-friendly
    While the inclusion of images and videos generally improves open- and click through rates, these elements must be responsive and mobile friendly.
  6. Don’t be Spammy
    If it looks and behaves like SPAM, it will be treated as such. Monitor email frequency against key metrics to optimise, and avoid ‘spammy’ subject lines that promise the earth.
  7. Don’t forget Opt-out!
    Google and Yahoo!’s email policy updates also require that all bulk emails include opt-out links for subscribers who no longer wish to receive emails from you. This is also a POPIA and GDPR requirement so should be an automatic function of your digital messaging platform that will also enhance deliverability.

Your bulk messaging platform should include features that make abiding by these principles a matter of course. With Inscribe from SYNAQ, you are assured of a digital messaging platform that helps your business communicate personally, reliably, and automatically using bulk email, SMS, and voice broadcasting – at scale:

  • Build engaging mobile-responsive, email and SMS campaigns with ease.
  • Automate client journeys.
  • Grow, manage, and segment client databases.
  • Integrate your tools with ours for a seamless flow of information across CRMs and productivity tools.
  • Track and optimise communication with actional insights and reporting tools.

Inscribe is safe, secure, and fully POPI and GDPR-compliant and, when coupled with Securemail, gives you a single partner in email authentication and bulk communication for accountability and 24/7 local customer service.


Navigating the complexities of email authentication might seem daunting, but you don't have to do it alone. SYNAQ specialises in configuring and managing these protocols, and can assist you in ensuring that your emails are authenticated, secure, and reliably delivered. Our expertise not only safeguards your communications but also positions your business as a trustworthy and professional entity in the eyes of your clients and partners.

By partnering with SYNAQ, you can focus on what you do best, knowing that your email security is in expert hands. Let's work together to ensure your emails always reach their intended destination, unimpeded and trusted.