Why are my emails going to spam?
Almost always authentication first, reputation second, content third, in that order. On 2026-08-10, 88% of the 498 business domains measured enforce DMARC, and 70.3% of them reject outright. This is the first day of the measurement, so there is no trend yet.
Check authentication before you touch a single word of copy
Rewriting subject lines is the most common first move and the least likely to fix anything. If SPF, DKIM and DMARC alignment are not right, no amount of copy editing changes the outcome, because the message is being judged before the content is read.
Three things have to be true on your sending domain: SPF authorises the servers you actually send from, DKIM signs with a key published under the sending domain, and DMARC alignment passes so the domain in your From address matches the one that authenticated. 43.2% of the domains measured today go as far as a strict SPF policy on their own mail, which tells you how normal this has become.
Today 1.2% of measured domains publish no DMARC record at all. That is the group where an unauthenticated message might still land, and it is exactly why intermittent delivery is so confusing to diagnose: the same broken setup succeeds against some recipients and fails against others.
Then reputation: volume, complaints and bounces
Mailbox providers score the sending domain and IP over time. A new domain sending a thousand messages on day one looks like exactly the thing spam filters exist to stop, whatever the content says. Ramp volume, keep the complaint rate low, and keep bounces low by verifying addresses before you send.
Bounces are the fastest way to lose a domain's reputation, and they are the easiest to prevent. A list that has not been verified will contain dead addresses and spam traps, and both are read as a signal that you did not get permission for the list.
Who is actually filtering your mail
Across the panel measured today, the mail is filtered by Proofpoint 33.9%, Microsoft 365 25.9%, Google Workspace 18.7%. That mix matters, because a security gateway in front of a mailbox applies its own rules on top of the mailbox provider's, and a message that lands in Gmail can still be quarantined by a gateway.
MTA-STS is the other signal worth watching: 5.8% of measured domains publish it, which requires your outbound connection to use valid TLS to reach them.
Content, last
Content matters least and gets the most attention. Once authentication and reputation are right, the things that still hurt are large images with almost no text, link shorteners, too many links, and a missing unsubscribe mechanism. A list-unsubscribe header is a requirement for bulk senders now, not a nicety.
Related questions
Why do my emails land in spam for some people but not others?
Because recipient domains do not agree on what to do with mail that fails authentication. Today 88% of measured domains enforce DMARC and 1.2% publish no DMARC record at all, so the same misconfigured send can be delivered by one and rejected by another. That pattern is a strong hint the problem is authentication, not content.
Will warming up a new domain fix spam placement?
Warmup helps reputation, which is the second factor, so it only helps once authentication is already correct. Warming a domain whose DKIM does not align just spends weeks building a reputation for mail that will keep failing.
How do I check whether my own domain is set up correctly?
Look up your own SPF, DKIM, DMARC and MX records and read what they actually say, rather than what you configured a year ago. Emailchaser's free deliverability test runs the same DNS checks used to build the panel measurement on this page.
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