5 Common Email Marketing Mistakes That Hurt Deliverability (And How to Fix Them)

Email marketing remains one of the most powerful tools for businesses to connect with customers — but only if your emails are actually getting delivered. Far too often, businesses unknowingly make technical mistakes that damage their email deliverability and hurt their entire marketing strategy.

Let’s dive into the five most common mistakes and how you can fix them.

1. Skipping Proper Email Authentication

If your domain isn’t properly authenticated with SPF, DKIM, and DMARC records, inbox providers may flag your emails as untrustworthy — or worse, block them entirely.

How to fix it: Set up and maintain SPF, DKIM, and DMARC correctly. Regularly review your records to ensure they align with any new email platforms or services you add.

2. Buying Email Lists: One of The Most Common Email Marketing Mistakes to Avoid

Purchasing email lists is a shortcut that almost always backfires. These lists often include outdated, invalid, or uninterested contacts, leading to high bounce rates, spam complaints, and domain reputation damage.

How to fix it: Focus on organic list growth. Use lead magnets, signup forms, and events to attract people who actually want to hear from you.

3. Sending From Free Email Addresses (Like Gmail or Yahoo)

Using a free email address (e.g., yourcompany@gmail.com) to send bulk marketing emails looks unprofessional — and triggers spam filters.

How to fix it: Send marketing emails from a domain you control (like hello@yourcompany.com) that has been properly authenticated.

4. Ignoring Engagement Metrics

Inbox providers like Gmail monitor how recipients interact with your emails. Low open rates, high unsubscribe rates, or minimal engagement can cause your future emails to be filtered to spam.

How to fix it:

• Regularly clean your lists to remove unengaged subscribers.

• Use segmentation to send more relevant content.

• Monitor engagement closely and adjust your strategy based on results.

5. Not Warming Up New Domains or IPs

If you suddenly send a large volume of emails from a brand-new domain or IP address, inbox providers view it as suspicious behavior.

How to fix it: Warm up gradually. Start by sending small batches of emails and slowly ramp up over a period of weeks, giving inbox providers time to trust your sending habits.

How Mailfixer Can Help Fix Email Marketing Mistakes

Mailfixer identifies and fixes the most common email marketing mistakes that hurt deliverability — from poor domain setup and cold list sends to missing authentication and spam triggers. We provide hands-on support to ensure your emails consistently reach the inbox.

Think your campaigns could perform better? Contact us here and let’s fix what’s holding you back.

Final Thoughts

Even small technical mistakes can drastically affect your email marketing results. The good news is, with the right setup, strategy, and ongoing support, you can avoid these pitfalls and consistently reach your audience.

At The Mail Fixer, we offer hands-on email deliverability services and technical support to ensure your email marketing engine runs smoothly and successfully. Whether you need help fixing existing issues or setting up a solid foundation, we’re here to help.

Ready to optimize your email marketing? Reach out to us today and let's get started!

Email Marketing Mistakes FAQs

What’s the most common mistake that affects email deliverability?

The most common mistake is failing to authenticate your domain using SPF, DKIM, and DMARC. Without these, your emails are more likely to be flagged as spam or rejected entirely by receiving servers.

How does poor list hygiene damage deliverability?

Sending emails to outdated or unengaged contacts increases bounce rates and spam complaints, which harms your sender reputation. Regularly cleaning your list helps maintain high engagement and inbox placement.

Why is using a generic or misleading subject line a bad idea?

Misleading subject lines can trigger spam filters and lead to higher unsubscribe or complaint rates. Always keep subject lines honest, relevant, and aligned with the content inside the email.