How do I check if my emails are going to spam?

Send test emails to accounts at Gmail, Yahoo, and Outlook, then check the spam folder. Use Google Postmaster Tools to monitor your domain reputation and spam rate. You can also use seed list testing services that check inbox placement across multiple providers.

What spam complaint rate is acceptable?

Gmail and Yahoo require spam complaint rates below 0.3%, but recommend staying under 0.1%. This means no more than 1 complaint per 1,000 emails sent. Consistently exceeding this threshold will damage your sender reputation and increase spam folder placement.

Do I need SPF, DKIM, and DMARC to avoid spam?

Yes. As of 2024, Gmail and Yahoo require SPF or DKIM for all senders, and bulk senders (5,000+ emails per day) must have all three: SPF, DKIM, and a DMARC policy. Microsoft announced similar requirements starting May 2025. Without proper authentication, your emails are far more likely to be filtered as spam.

Can email content trigger spam filters?

Yes. Spam filters analyze content for patterns associated with spam, including excessive use of words like 'free' or 'urgent,' too many links or images, misleading subject lines, and poor text-to-image ratios. However, content filtering is secondary to reputation and authentication signals.

How long does it take to fix spam folder issues?

It depends on the cause. Authentication issues can be resolved within 24-48 hours once DNS records propagate. Reputation recovery typically takes 2-4 weeks of consistent good sending practices. Blocklist removal varies from hours to weeks depending on the blocklist operator.

Why Are My Emails Going to Spam?

We see this question constantly from senders of all sizes. You have spent time crafting your message, your recipients have opted in, yet your emails still land in the spam folder. Understanding why this happens is the first step to fixing it.

Mailbox providers process billions of emails daily. Gmail alone handles over 1.8 billion accounts. To protect users from unwanted mail, they use sophisticated filtering systems that evaluate every incoming message against hundreds of signals. When your email fails these checks, it goes to spam.

The 8 Main Reasons Emails Go to Spam

1. Missing or Broken Email Authentication

Email authentication tells mailbox providers that you are who you claim to be. There are three protocols that work together:

SPF (Sender Policy Framework) lists which servers are allowed to send email for your domain
DKIM (DomainKeys Identified Mail) adds a digital signature to verify the message was not altered in transit
DMARC (Domain-based Message Authentication, Reporting and Conformance) tells mailbox providers what to do when SPF or DKIM checks fail

As of 2024, Gmail and Yahoo require authentication for all senders. Bulk senders (those sending more than 5,000 messages per day to their users) must have SPF, DKIM, and a published DMARC policy. Microsoft announced similar requirements starting May 2025.

If your authentication is missing or misconfigured, mailbox providers have no way to verify your legitimacy. The result is spam folder placement or outright rejection.

2. Poor Sender Reputation

Your sender reputation is a score that mailbox providers assign to your sending IP addresses and domains based on your historical sending behavior. Factors that damage reputation include:

High bounce rates from sending to invalid addresses
Spam complaints from recipients
Sending to spam traps (addresses designed to catch bad senders)
Sudden spikes in sending volume
Low engagement rates (few opens or clicks)

You can check your reputation using tools like Google Postmaster Tools, Microsoft SNDS, or Sender Score. A reputation score below 70 (on a 100-point scale) typically indicates deliverability problems.

3. High Spam Complaint Rates

When recipients click "Report Spam" or "Mark as Junk," that signal goes directly to the mailbox provider. Gmail and Yahoo require senders to maintain spam complaint rates below 0.3%, with a recommended target of under 0.1%.

To put that in perspective: if you send 10,000 emails and 30 people mark you as spam, you have hit the 0.3% threshold. Three complaints per thousand is all it takes.

Common causes of complaints include sending too frequently, making unsubscribe difficult, or emailing people who do not remember opting in.

4. Sending from a Free Email Domain

Using a free email address like gmail.com or yahoo.com for business email, especially bulk sending, significantly increases spam risk. These domains cannot be properly authenticated with DKIM for third-party sending, and mailbox providers treat them with extra scrutiny.

Use a custom domain that you control and can authenticate properly.

5. Poor List Hygiene

Email lists decay at roughly 22% per year as people change jobs, abandon addresses, or switch providers. Sending to stale lists results in:

Hard bounces from invalid addresses
Spam trap hits from recycled addresses
Low engagement from disinterested recipients

Regular list cleaning, removing addresses that have not engaged in 90+ days, and using double opt-in for new subscribers all help maintain list quality.

6. IP or Domain Blocklisting

Blocklists (sometimes called blacklists) are databases of IP addresses and domains known to send spam. Major blocklist operators include Spamhaus, Barracuda, and SpamCop. If your sending infrastructure appears on these lists, many mailbox providers will automatically filter your messages to spam or reject them entirely.

You can check blocklist status using MXToolbox or similar services. Removal typically requires fixing the underlying problem and submitting a delisting request to each blocklist operator.

7. Content That Triggers Filters

While content filtering is less important than reputation and authentication, certain patterns can still trigger spam filters:

Excessive use of spam-associated words ("free," "act now," "limited time")
Too many links, especially to suspicious domains
Poor text-to-image ratio (too many images, not enough text)
Misleading subject lines that do not match content
Missing or fake physical address

That said, we have seen perfectly legitimate emails with the word "free" reach the inbox, and spam with no obvious triggers get filtered. Content matters, but reputation matters more.

8. Missing Unsubscribe Functionality

Gmail and Yahoo now require bulk senders to support one-click unsubscribe using the List-Unsubscribe header. Unsubscribe requests must be processed within two days.

Making unsubscribe easy actually helps deliverability. When recipients cannot find an unsubscribe link, they click "Report Spam" instead, which damages your reputation far more than an unsubscribe.

How to Diagnose Your Spam Problem

Start by checking these areas in order:

Authentication: Use MXToolbox or Google Admin Toolbox to verify your SPF, DKIM, and DMARC records are correctly configured
Reputation: Check Google Postmaster Tools for your domain reputation and spam rate
Blocklists: Run a blocklist check on your sending IPs and domains
Bounce rate: Review your bounce reports for patterns (too many hard bounces indicate list quality issues)
Complaints: Check your feedback loop reports if you have enrolled with major providers

How to Fix Spam Folder Placement

Fix Authentication First

Authentication issues are the most common cause we see. Verify that:

Your SPF record includes all legitimate sending sources and does not exceed the 10 DNS lookup limit
DKIM is properly configured with matching public and private keys
Your DMARC record is published and your From domain aligns with either SPF or DKIM

DNS changes typically propagate within 24-48 hours.

Clean Your List

Remove addresses that have not opened or clicked in the past 90 days. Run your list through a verification service to identify invalid addresses before sending. Implement double opt-in for new subscribers.

Warm Up Gradually

If you are sending from a new IP or domain, or resuming sending after a long pause, increase volume gradually over 4-8 weeks. Start with your most engaged subscribers and slowly add older segments.

Make Unsubscribe Easy

Include a clear unsubscribe link in every message. Implement the List-Unsubscribe header for one-click unsubscribe support. Process opt-outs within 48 hours.

Monitor Continuously

Set up Google Postmaster Tools and monitor your domain reputation weekly. Enroll in feedback loops with major mailbox providers to receive complaint notifications. Check blocklist status regularly.

When Spam Filtering is Actually Working Correctly

Sometimes emails go to spam because they should. If you are sending to people who did not ask to receive your messages, or if you purchased an email list, spam filters are doing their job.

The foundation of good deliverability is permission. Send only to people who have explicitly opted in to receive your emails, send content they expect, and make it easy to opt out. Everything else is optimization on top of that foundation.