Why your emails land in spam (and the fix)

You’ve poured time, strategy, and creativity into your latest email campaign, only to find it buried in spam folders. It’s frustrating, demoralizing, and, unfortunately, common.

In email marketing, deliverability isn’t optional. It’s the foundation of everything. If your message doesn’t reach the inbox, nothing else (content, design, segmentation) matters.

In this post, we’ll break down:

1. Why emails go to spam

2. How to stay out of spam

3. What actions you can take today to improve deliverability

Let’s dive in.

Why emails go to spam

Here are some reasons why your mail may be going to spam, but it can be one or many issues:

1. Your technical setup isn’t complete

Inbox providers like Gmail and Outlook use technical protocols to determine whether your emails are legitimate or suspicious. If you’re missing these signals, your email is more likely to get flagged or blocked.

• SPF confirms you’re sending from an authorized server

• DKIM verifies the content hasn’t been tampered with

• DMARC tells providers how to handle emails that fail SPF or DKIM

Without proper setup, you’re sending red flags literally.

Your IP and domain reputation also matter. If you’ve inherited a domain with a poor track record (spam complaints, high bounce rates), you’ll start at a disadvantage.

2. Your list quality is hurting you

Deliverability lives and dies by your email list.

• Bought lists are often filled with spam traps, invalid addresses, or unengaged users

• Old or inactive lists lower engagement, which hurts your sender score

Even worse? If people start marking your emails as spam, inbox providers will assume your future sends are also unwelcome.

3. Your sending behavior looks suspicious

If you’re blasting thousands of emails from a brand-new domain, expect trouble.

• Inconsistent sending volume raises red flags

• Sudden spikes in sends without warming your IP can lead to throttling or blocking

• Irrelevant messaging leads to low engagement, which inbox filters pick up on fast

4. Your content triggers spam filters

Inbox algorithms scan your subject lines, body copy, formatting, and links. If something looks sketchy or even just lazy you’re at risk.

• Avoid spammy language (“FREE,” “Act Now,” “Urgent!!!”)

• Don’t rely on image-only emails or giant buttons

• Balance text and visuals; keep links relevant

• Minimize attachment use

Above all: engagement matters. Low opens, low clicks, and high unsubscribes signal that your content doesn’t belong.

How to stay out of spam: your inbox playbook

Here’s a clear checklist to improve inbox placement:

Final thoughts

Even the best-designed emails fail if they don’t reach the inbox.

The good news? Most spam issues are fixable with the right foundation, smart targeting, and ongoing monitoring. Inbox placement isn’t luck. It's a strategy.