Why your emails land in spam — and the levers that actually move inbox placement.
Deliverability is the percentage of your emails that reach the inbox — not the "sent" count, and not even the "delivered" count. You can have a 99% delivered rate and still sit in spam folders. In 2026, with Gmail and Yahoo enforcing stricter sender requirements, getting this right is the difference between a campaign that converts and one nobody sees.
These DNS records prove you're allowed to send from your domain. SPF lists the servers permitted to send. DKIM cryptographically signs your mail. DMARC tells receivers what to do if a message fails the first two. Since 2024, bulk senders to Gmail/Yahoo must have all three — without them, mail is rejected or spam-foldered outright.
Mailbox providers score your sending IP and domain based on history: complaint rates, spam-trap hits, and bounce rates. A clean record earns inbox placement; a poor one earns the spam folder or outright blocks. Reputation is slow to build and fast to lose.
This is the lever most people ignore — and it's the biggest. Sending to invalid, abandoned, or spam-trap addresses spikes your bounce and complaint rates, which torpedoes reputation, which sinks deliverability for every message after. One bad list can poison a domain for weeks.
You can perfect SPF/DKIM/DMARC and still tank if you mail a dirty list. Verifying a list before you send removes invalids, disposables, and role addresses, so your bounce rate stays low and your reputation stays intact. It's the cheapest, highest-leverage thing you can do for deliverability — especially before a first send to a new or purchased list.
Start with the list. Verify your first 100 emails free →