Why Are My Emails Going to Spam?
Investigate spam placement by checking authentication, audience permission, content, reputation, blocklists, unsubscribe handling, and volume changes. Use message headers and provider logs to identify which condition changed.
This is the troubleshooting companion to our email deliverability guide.
Reviewed by the Loops team · September 9, 2026.
Check the current Gmail sender guidance and Yahoo sender guidance for authentication and unsubscribe requirements. Your team still owns recipient permission and audience quality.
Start with a recent affected message and compare it with one that delivered normally. Check the evidence below and change one condition at a time where possible so you can tell which repair helped.
1. Authentication failures (SPF, DKIM, DMARC)
Authentication failures can cause filtering or rejection. Google requires senders of 5,000 or more messages per day to personal Gmail accounts to use SPF, DKIM, and DMARC. Yahoo requires the same controls for senders it classifies as bulk, but it does not publish a numeric volume threshold. Noncompliant mail may be filtered or rejected.
SPF says which servers are allowed to send for your domain.
DKIM cryptographically signs each message so the recipient can verify it was not tampered with.
DMARC publishes a policy for messages where neither SPF nor DKIM passes with alignment to the From domain, and provides reporting.
2. Poor list quality, no consent, or purchased lists
Purchased or scraped addresses and unclear signup permission put recipients at risk of unwanted mail. Check imports for invalid addresses that cause hard bounces, and track complaints by signup source. Pause a problematic source while you establish how its contacts joined.
The fix. Send marketing only with the required permission and honor opt-outs. Loops double opt-in gates Form endpoints. It does not automatically gate API contact creation. Review permission separately for API writes and imports. Investigate inactive contacts before deciding whether to pause further marketing. Maintaining a clean list includes reviewing signup sources, permissions, and delivery failures.
3. Spam-trigger content and formatting
Content and links can affect filtering, but there is no universal spam-word list or text-to-image ratio that guarantees inbox placement. Inspect warnings on the affected message and test changes to the content or links.
All-image emails can become unreadable when images are blocked. Keep essential information and actions available as text.
Sketchy or mismatched links hurt. Loops warns that shortened YouTube links (youtu.be) can be flagged as phishing by Gmail. Its Shortened YouTube links warning recommends using full YouTube URLs. Avoid stacking URL shorteners and redirects.
Spammy subject lines and bodies can misrepresent the message. Use an accurate subject and sender name. Avoid fake replies, misleading claims, and excessive punctuation.
Send a test with the actual content and links, then inspect the result at the affected mailbox provider. Use full destination URLs where possible, verify redirect chains, and make essential information readable when images are blocked. A check with rspamd can provide another diagnostic signal. It does not predict every mailbox provider’s filtering.
4. Low engagement and poor sender reputation
Mailbox providers consider sending history and recipient feedback when filtering mail. Complaints are a direct signal of unwanted messages. Missing opens alone are less useful because image blocking and privacy features affect tracking. Compare provider reputation data with recent changes in audience, volume, and content.
The fix. Send relevant mail to engaged people on a steady cadence. Welcome new subscribers immediately with an automated workflow while intent is highest, then keep a consistent rhythm rather than going dark for months and blasting. Suppress or sunset chronically disengaged contacts. Watch your numbers in Google Postmaster Tools and follow Google’s recommendation to keep reported spam rates below 0.1% and avoid ever reaching 0.3%. Check Yahoo’s separate complaint reporting for Yahoo traffic.
5. Blocklists
Some receivers consult public domain or IP blocklists when filtering mail. A listing can affect those receivers, but it does not establish that every provider will reject every message. Compare the listing with delivery response codes and the affected recipient domains.
The fix. Check your domain and IP against the major blocklists with a tool like MXToolbox. If you are listed, fix the underlying cause first, then follow each blocklist’s delisting process. On managed infrastructure like Loops, IP reputation and delisting are handled for you. Your job is to not generate the complaints and traps that get a shared IP flagged.
6. Broken or missing unsubscribe
A recipient who cannot find an unsubscribe link may report the message as spam. For bulk marketing and subscribed messages, Gmail requires RFC 8058 one-click unsubscribe. Yahoo accepts the mailto method and highly recommends RFC 8058 POST. Both require a functioning list-unsubscribe header, a visible body link, and processing unsubscribe requests within two days.
The fix. Put an obvious unsubscribe link in every marketing email and process opt-outs immediately. Loops automatically handles bounces, unsubscribes, and spam complaints for you, so opt-outs are honored and suppressed without manual work. Check that your contact-sync jobs preserve those opt-outs.
7. Sudden volume spikes and no warming
A sharp increase in sending volume can lead receivers to defer or filter messages, particularly when a domain or IP has little history. A move to a new domain or IP changes the sending identity. Monitor the affected traffic separately.
The fix. Ramp gradually. New senders should start on a subdomain, keep early volume conservative, and grow steadily so engagement data accrues before the big campaigns. Keep a consistent cadence rather than long silences punctuated by blasts. If you are migrating domains, plan for a reputation reset and ramp again.
Collect evidence from an affected message
These checks narrow the investigation. More than one condition may need attention.
Send a test to a Gmail and a Yahoo address. Inbox or spam? If the message is in spam, record the warning banner and its wording.
Check authentication. Open the test, choose Show Original in Gmail. SPF, DKIM, and DMARC should all read PASS. Any FAIL or none is your top suspect (cause 1).
Check your spam-complaint rate in Google Postmaster Tools. Google recommends staying below 0.1% and avoiding 0.3%. Use the provider’s reported metric and scope.
Check your bounce rate. Compare recent bounces with your baseline and inspect the full error codes. Separate invalid addresses from temporary failures and policy rejections.
Scan blocklists with MXToolbox for your domain and sending IP (cause 5).
Eyeball the email. Heavy on images, light on text? Shortened or redirected links? An unsubscribe link you can actually find? (causes 3 and 6).
Look at recent volume. Did sends spike, or did you just change domains? (cause 7).
What Loops handles
Loops operates sending infrastructure and supplies controls for domain setup, subscription state, and delivery failures. Your team still owns permission, audience selection, and content.
Authentication is guided and partly automatic. DKIM signs every message from your first send. Loops hands you ready-to-copy SPF, DKIM, and DMARC records and a Verify Records button, so you can pass the 2024 Gmail/Yahoo requirements without hand-rolling DNS.
Bounces, complaints, and unsubscribes are handled automatically. Loops suppresses reported hard bounces and complaints and honors marketing opt-outs. Keep those states intact when syncing contacts.
Content needs testing. Inspect message rendering and links, and review provider responses when a message is filtered.
Form confirmation is available. Built-in double opt-in requires confirmation for Form endpoints. API-created contacts and imports need separate permission checks.
Managed infrastructure. Loops operates sending IPs and handles delivery feedback. Monitor your own audience and complaint trends and work with support on infrastructure issues.
Frequently asked questions
Why are my emails going to spam all of a sudden?
How do I stop my emails from going to spam?
Do I really need SPF, DKIM, and DMARC?
Does Loops set up SPF, DKIM, and DMARC for me?
What spam-complaint rate is too high?
Can the content of my email send it to spam?
Will buying an email list hurt deliverability?
How long until my deliverability recovers after a problem?
Related: email deliverability best practices and the best time to send email, and the 12 best email deliverability tools roundup.
Looking for more? Browse all email guides and resources.