Improving deliverability is not one change — it is a system. Here is the practical playbook: what to fix, in what order, and how to verify each fix works.
This is non-negotiable. Gmail and Yahoo now require SPF, DKIM and DMARC for bulk senders. Check your records with our checker guide or a free GlockApps test. Fix any failures before doing anything else.
Remove hard bounces immediately. Suppress soft bounces after 3 consecutive failures. Remove subscribers who have not engaged (opened or clicked) in 6–12 months. Never add purchased addresses.
Run an email blacklist check. Check sender reputation via Google Postmaster Tools and Microsoft SNDS. Fix any issues before increasing volume.
Start by testing your current placement — 2 free tests with GlockApps.
Run free testAvoid common spam triggers (spammy subject lines, excessive links, image-only emails). Include a visible, working unsubscribe link. Test with a spam checker before every major send.
Run inbox placement tests before campaigns. Monitor placement over time. Set up blocklist and auth monitoring alerts. Deliverability is not a one-time fix — it is ongoing maintenance.
Run a free deliverability test with GlockApps and check your inbox placement across Gmail, Outlook and Yahoo, plus spam score and blocklist status.
Start with 2 free tests →