Deliverability Guide
Why are my emails going to spam?
Legitimate email lands in spam for a short list of reasons: missing or misaligned authentication records (SPF, DKIM, DMARC), a damaged sender reputation, DNS or platform misconfiguration, a new domain with no sending history, or sending practices that look like bulk mail to the filters. Almost every case is diagnosable, and most are fixable.
Last reviewed: August 22, 2026 · Part of our email deliverability services resources
The five causes, in the order to check them
Work through these in sequence. Fixing a later one while an earlier one is still broken wastes the effort.
1. Authentication
SPF, DKIM, and DMARC tell receivers the mail is genuinely yours. Missing records, a wrong record, or a system sending on your behalf that is not listed all fail the check — and failed authentication is the most common single cause.
2. Configuration
DNS changes, platform migrations, and split delivery between two mail systems leave gaps: the wrong MX, a stale record, or a relay that rewrites the sender. Inherited setups are the usual source.
3. Sender reputation
Receivers score your domain and sending addresses on history: complaints, bounces, blacklistings, and engagement. Reputation damage is slow to earn and slow to repair.
4. Sending practices
Sudden volume, purchased lists, cold sends from the primary domain, and low engagement all read as bulk mail to the filters, whatever the authentication says.
5. Content and links
Least common as a root cause, but shortened links, heavy images with little text, and mismatched link domains add to a score that is already borderline.
Then: verify
Re-send to test mailboxes across providers and read the Authentication-Results headers. A fix that is not verified is a guess.
What the fix involves
Authentication is repaired across every system that sends for you — your mail platform, marketing tools, CRM, invoicing, and transactional senders — so the records match reality rather than the last person's guess. Platform settings on Microsoft 365 and Google Workspace are corrected alongside DNS.
Reputation is rebuilt with volume and practice changes rather than tricks, and the whole process ends with written documentation of what was changed and what to keep doing. Authentication fixes take effect quickly; sender reputation improvement takes 2-4 weeks.
What no one can promise
- Guaranteed inbox placement — receivers decide, not senders
- A placement percentage
- An instant reputation reset
- Fixes without access to DNS and the sending platforms
Frequently Asked Questions
How do I check whether SPF, DKIM, and DMARC are set up?
Send a message to a mailbox you control and open the message headers. The Authentication-Results line shows a pass or fail for each of SPF, DKIM, and DMARC. Missing or failing results point directly at the records to fix. A free deliverability audit does this across every system that sends on your behalf.
Will fixing DMARC stop my emails going to spam?
It is necessary, not sufficient. Authentication proves the mail is really from you; it does not repair a damaged sender reputation or fix sending practices. Most real cases need authentication corrected first, then reputation and sending habits addressed.
Why do my emails go to spam only with some recipients?
Each receiving provider scores mail differently and keeps its own reputation data. A configuration that one provider tolerates, another rejects. Problems that show up only at certain destinations usually trace back to a specific authentication gap or a reputation issue with that provider's filters.
Does a new domain go to spam more often?
Usually, yes. A new domain has no sending history, so filters have nothing to trust. Building reputation gradually on a correctly authenticated domain is the fix; sending a large volume on day one is the fastest way to make a new domain look like spam.
How long does it take to fix deliverability?
Authentication fixes take effect as soon as the DNS records propagate. Sender reputation improvement takes 2-4 weeks. No provider controls inbox placement, so the honest commitment is diagnosis, repair, and reporting rather than a placement guarantee.
Find out which cause is yours.
Request a free deliverability audit. We check authentication, configuration, and reputation across every system that sends on your behalf, and reply with the right next step and a written quote within 24 hours.
Request Your Free Deliverability Audit