Why Your Emails Go to Spam (And How to Fix It)

What Is Email Deliverability?

Email deliverability is the ability of your emails to actually land in the recipient’s inbox — not their spam or junk folder. It’s affected by your domain’s reputation, your email authentication setup, the content of your messages, and how recipients interact with them.

Even if your emails are “sent successfully,” that doesn’t mean they were delivered to the inbox. A surprising number of legitimate business emails end up in spam, and most senders never know.

Step 1: Set Up Email Authentication (SPF, DKIM, DMARC)

These three DNS records are the foundation of email deliverability. Without them, email providers have no way to verify that you’re a legitimate sender.

SPF (Sender Policy Framework)

SPF tells receiving mail servers which IP addresses and services are allowed to send email on behalf of your domain. Without it, anyone can spoof your domain.

Example SPF record:

This record says: “Only Google Workspace and SendGrid are authorized to send email for this domain. Soft-fail everything else.”

DKIM (DomainKeys Identified Mail)

DKIM adds a cryptographic signature to every outgoing email. The receiving server checks this signature against a public key published in your DNS. If it matches, the email hasn’t been tampered with.

Example DKIM DNS entry (TXT record):

DMARC (Domain-based Message Authentication, Reporting & Conformance)

DMARC ties SPF and DKIM together and tells receiving servers what to do when authentication fails. It also gives you reports on who’s sending email using your domain.

Example DMARC record:

This record says: “If SPF or DKIM fails, quarantine the message (send to spam). Send aggregate reports to this address.”

Step 2: Monitor Your Domain & IP Reputation

Your domain reputation is a score that email providers assign based on your sending history. Things that hurt your reputation:

• High bounce rates (sending to addresses that don’t exist)
• Spam complaints from recipients
• Sending to purchased or outdated lists
• Sudden spikes in volume

You can check your domain reputation using tools like Google Postmaster Tools, Microsoft SNDS, or third-party services like Sender Score.

Shared vs. Dedicated IP

If you’re using a shared IP (common with services like Mailchimp, SendGrid, or HubSpot on lower-tier plans), your deliverability is partly determined by other senders on that same IP. If one of them sends spam, it can drag your reputation down.

A dedicated IP gives you full control over your sending reputation, but it requires consistent volume. If you send fewer than 50,000 emails per month, a shared IP with a reputable provider is usually the better choice.

Step 3: Include a Proper Unsubscribe Mechanism

Since February 2024, Google and Yahoo require bulk senders to include a one-click unsubscribe option. This isn’t optional — emails without it are more likely to be filtered as spam.

Your email headers should include:

Most modern email marketing platforms handle this automatically, but it’s worth verifying that yours does.

Step 4: Watch Your Content & Formatting

Email content still matters for deliverability. Spam filters evaluate:

• Subject lines: Avoid ALL CAPS, excessive punctuation (!!!), and spammy phrases like “Act now” or “Free offer.”
• Image-to-text ratio: Emails that are mostly images with very little text often trigger spam filters.
• Links: Use your own domain for links, not URL shorteners. Too many links in one email can also be a flag.
• HTML quality: Broken HTML or sloppy formatting can hurt deliverability.

Step 5: Practice Good List Hygiene

Maintaining a clean list is one of the most effective things you can do for deliverability:

• Remove hard bounces immediately. Continuing to send to invalid addresses hurts your reputation.
• Re-engage or remove inactive subscribers. If someone hasn’t opened your emails in 6–12 months, send a re-engagement campaign or remove them.
• Never buy email lists. This is the fastest way to destroy your domain reputation and potentially get blacklisted.
• Use double opt-in. Confirm new subscribers actually want to receive your emails.

Step 6: Consider BIMI (Brand Indicators for Message Identification)

BIMI lets you display your brand’s logo next to your emails in the inbox. It requires a valid DMARC policy set to p=quarantine or p=reject, plus a Verified Mark Certificate (VMC) from a certificate authority.

BIMI doesn’t directly improve deliverability, but it increases brand recognition and trust, which can improve open rates and reduce spam complaints over time.

Good deliverability isn’t a one-time fix — it’s an ongoing practice. Set up the foundations, monitor your reputation, and keep your list clean. Your emails will reach the people who actually want to read them.