Why Your Emails Go to Spam (and the 12 Fixes That Actually Work)

"Our emails are going to spam" is the most common deliverability complaint — and the least specific. Spam placement is a score, not a single switch, and mailbox providers compute it from four inputs. Here they are in priority order, with the fixes that actually move each one.

Root cause 1: authentication failures

If SPF, DKIM, or DMARC fail — or pass without alignment to your visible From: domain — you look like a spoofer to every major provider.

Fix 1 — verify all three records. Send a test to a Gmail address, open Show original, and confirm spf=pass, dkim=pass, dmarc=pass. Anything else is your first project. MailBlastr's domain setup generates the records and verifies them continuously.

Fix 2 — align your From: domain. Send from an address on your authenticated domain, never from a free-mail From: (gmail.com From: addresses fail DMARC by design at Gmail itself).

Fix 3 — use a subdomain strategy. Send marketing from mail.acme.com and transactional from acme.com (or separate subdomains) so a newsletter mistake can't drag down password resets. Per-domain reputation isolation is the reason multi-domain support matters in a provider.

Root cause 2: sender reputation

Providers score your sending domain and IP on history: bounce rates, complaint rates, spam-trap hits, volume consistency.

Fix 4 — watch the two rates that matter. Keep hard bounces under 2% and complaints under 0.1% (Gmail's published ceiling is 0.3% — treat that as a cliff edge, not a target). Rising bounces on a send is your earliest smoke alarm; webhook events give you the per-recipient data in real time.

Fix 5 — warm up new domains. Reputation is earned with gradual, consistent volume to engaged recipients. A structured warm-up schedule beats any tool that promises instant scale.

Fix 6 — keep volume consistent. 500 emails daily beats 15,000 on the first of each month. Spiky patterns read as botnet behavior; if you must spike, ramp over several days.

Root cause 3: list hygiene

Every stale address on your list is a future bounce, and old lists accumulate spam traps — addresses providers plant specifically to catch senders who don't clean.

Fix 7 — suppress bounces automatically. A hard bounce must never be mailed again. MailBlastr suppresses bounced, complained, and unsubscribed addresses on every future send automatically — if your current provider doesn't, that alone is a reason to switch.

Fix 8 — never buy or scrape lists. Purchased lists are where spam traps live. The short-term reach is not worth the domain damage, which takes months to repair.

Fix 9 — sunset the unengaged. Recipients who haven't opened in 6–12 months should get one re-engagement attempt, then removal. A smaller engaged list outperforms a large dead one on every metric that matters, including revenue. See audience hygiene for a working policy.

Root cause 4: engagement signals

Gmail in particular weighs how recipients treat your mail: opens, replies, deletes-without-reading, spam reports, rescues from the spam folder.

Fix 10 — make unsubscribing effortless. A visible unsubscribe link plus RFC 8058 one-click unsubscribe headers turns "I'm done with this" into an unsubscribe instead of a spam complaint. One is neutral; the other poisons your reputation.

Fix 11 — send what people signed up for. Frequency and content should match the expectation set at signup. The fastest way to generate complaints is surprising people.

Fix 12 — front-load value in the first send. The first emails to a new address teach the provider whether your mail gets engagement. A strong welcome message that people actually open sets the baseline for everything after.

What about spam words, image ratios, and HTML tricks?

They exist in filtering systems but sit far down the priority list. A trusted sender writing "50% off — FREE shipping" inboxes fine; an untrusted sender writing perfect prose doesn't. If you're debugging spam placement by rewording subject lines before checking authentication and bounce rates, you're reorganizing deck chairs.

The order of operations

1. Authentication passing and aligned (fixes 1–3)
2. Bounce/complaint rates measured and under thresholds (fixes 4–6)
3. List cleaned and suppression automated (fixes 7–9)
4. Engagement mechanics honest (fixes 10–12)

Run through that list and the deliverability insights on each send, and "why are we in spam?" turns into a measurable checklist. If your current provider gives you none of this visibility, MailBlastr's free tier includes tracking, suppression, and 30-day logs — enough to diagnose a spam problem before paying anything.