# Why Is My Newsletter Going to Spam?

Source: https://www.tryletterhead.com/blog/why-newsletter-going-to-spam.html

When a newsletter starts landing in spam, the instinct is to blame a word in the subject line. That's rarely it. Mailbox providers like Gmail and Outlook mostly decide based on who you are and how your readers react to you.

Check these in order. Most problems turn up in the first two.

## 1. Authentication

Gmail and Yahoo have required SPF, DKIM and a DMARC policy from anyone sending more than 5,000 messages a day to their users since February 2024. Outlook.com has rejected bulk mail that fails them since May 2025.

A missing or broken record is the most common reason a newsletter that used to land fine suddenly doesn't, often right after a platform switch or a DNS change.

_Free tool · DMARC checker_

Is your DMARC policy where Gmail and Yahoo need it?

Type your sending domain to see your DMARC, SPF and DKIM records in plain English. No signup.
[Check your DMARC](../tools/dmarc-checker.html)

## 2. Who you're sending to

Mailbox providers watch how your readers behave. Mail sent to addresses that bounce, or to people who stopped opening months ago, tells them your email isn't wanted.

- Remove hard bounces after every send.

- Find readers who haven't opened in months, send one re-engagement email, and stop sending to the ones who don't respond.

- Check suspicious signups before they go on the list.

_Free tool · Ghost Finder_

Is this address real, or a ghost?

Check one address before it goes on your list: will it bounce, is it a typo, a throwaway or a role address like info@? No signup.
[Check an address](../tools/ghost-finder.html)

## 3. Complaints

Every time a reader marks your newsletter as spam, it counts against you. Google asks bulk senders to keep their spam rate, as shown in Google Postmaster Tools, below 0.3%.

Complaints rise when people don't remember signing up, when the email isn't what they expected, and when the unsubscribe link is hard to find. A clipped email, where Gmail hides the footer, makes that last one worse.

## 4. Sudden changes

A new domain, a new platform or a big jump in volume all look suspicious until a mailbox provider has history with you. Ramp up gradually when you can, and send to your most engaged readers first.

## 5. Content

Content matters least of the five, but it still matters. Links that don't work, very heavy HTML and emails that look nothing like what readers signed up for can all hurt.

_Free tool · Preflight_

Check your SPF, DKIM and DMARC in seconds.

Type your sending domain, or paste an email to catch links that won't work and Gmail's ~102KB clip. No signup.
[Open Preflight](../tools/preflight.html)

## How to see what Gmail thinks

[Google Postmaster Tools](https://postmaster.google.com/) is free and shows how Gmail sees your domain: spam rate, authentication and domain reputation. It's the closest thing to a straight answer you'll get from a mailbox provider.

Then look at your own numbers by mailbox provider. If opens fall at one provider and not the others, the problem is at that provider.

## In Letterhead

Letterhead checks every issue before you send for links that won't work, bounce risk, readability and Email Weight. Every newsletter also sorts its readers into engagement groups, Ghosts included, so you can see how many unengaged readers you're sending to before you hit send.

## Frequently asked questions

**Can one word in the subject line send my newsletter to spam?**
Rarely on its own. Authentication, list health and complaints matter far more.

**How do I test whether my newsletter goes to spam?**
Check your content and your domain's setup with the [email spam test](../tools/email-spam-test.html), then watch your inbox placement and Google Postmaster Tools over a few sends.

**Will fixing SPF, DKIM and DMARC get me out of spam?**
It's required, but it isn't always enough. Gmail and Yahoo also weigh complaints and engagement.

#deliverability #spam #how-to

_Keep reading_

## More on this topic.
[Email Deliverability Best Practices: How to Stay in the Inbox (and Out of Spam)
Learn how to maintain high email deliverability, protect your sender reputation, and keep your emails out of spam with these best practices and technical tips.
Read the post](../blog/email-deliverability-best-practices.html)[The Ultimate Guide to a Newsletter Spam Test
A newsletter spam test helps you spot issues before you send. Learn how to improve deliverability and keep your emails out of the spam folder.
Read the post](../blog/newsletter-spam-test.html)[How to Avoid Spam Filters and Improve Newsletter Deliverability
Learn how to avoid spam filters for newsletters with practical tips on sender reputation, content, and technical setup to keep your emails in the inbox.
Read the post](../blog/avoid-spam-filters-newsletters.html)

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