Email Deliverability: What It Is and How to Improve It

What is email deliverability?

Email deliverability is the ability of your email to reach your subscribers' inboxes. It goes further than a simple bounce check.

Here's the distinction that matters:

• Delivery means the receiving server accepted your email.
• Deliverability means it avoided the spam folder and landed in the inbox.

Subtle, but critical. You can hit a 100% delivery rate and still have every email sitting in junk.

What impacts deliverability?

1. Your sender reputation

Think of it as a credit score for email. ISPs like Gmail and Outlook track your sending behaviour:

• Are your subscribers opening your emails?
• Are they clicking, or just ignoring?
• Are people reporting you as spam?

Consistent, clean sending earns you a good reputation. A poor reputation earns you the spam folder.

2. Authentication settings

Three acronyms that carry more weight than most marketers realise:

• SPF (Sender Policy Framework) tells receiving servers which IP addresses are authorised to send on your behalf.
• DKIM (DomainKeys Identified Mail) adds a digital signature to your emails, confirming the message came from you and was not altered in transit.
• DMARC (Domain-based Message Authentication, Reporting and Conformance) ties SPF and DKIM together and tells email providers what to do when something looks suspicious.

Without these in place, you look like a spammer, even if you are not one.

3. Your list quality

Bad data leads directly to bad deliverability.

• Holding onto old, inactive addresses increases hard bounces.
• Bought lists are a reliable way to rack up bounces and spam complaints fast.

4. Your email content

Spam filters scan everything:

• Trigger words like 'free', 'buy now', or 'guarantee'
• Format problems such as too many images, all-caps subject lines, or broken HTML
• Suspicious-looking links

If the content reads like spam, it gets treated like spam.

How can you improve your deliverability?

You do not need to be technical. You need a checklist and some consistent habits.

1. Set up proper authentication Get SPF, DKIM, and DMARC configured at the domain level. Your email platform or agency can walk you through this.

2. Send from a custom domain Drop the Gmail address for bulk sending. Use a proper business email domain (like news@yourbrand.co.za) and warm it up before sending at volume.

3. Clean your list regularly Remove inactive and dormant subscribers. Handle bounce data correctly so problem addresses do not keep dragging down your metrics.

4. Use double opt-in Yes, it adds a step. That step confirms the person genuinely wants your emails and that their address is real.

5. Send consistently Erratic sending patterns raise flags. A regular cadence builds trust with ISPs and keeps your sender reputation stable.

6. Segment your database Send relevant content to the right people. A brand-new subscriber should not be getting the same email as someone who has been on your list for two years.

7. Monitor engagement Watch open rates, clicks, unsubscribes, and spam complaints. If engagement drops, deliverability follows. Run re-engagement campaigns before removing cold contacts.

8. Keep your design clean Make it look like something a real person put together. Heavy image-to-text ratios, broken layouts, and cluttered formatting all push you toward spam.

The bottom line

Good deliverability is built through consistent habits, not luck. Each email you send either adds to your reputation or chips away at it.

Want help improving your deliverability? TouchBasePro works behind the scenes to get you into more inboxes and out of spam.