Warming up
Free tools
Free email deliverability tools.
No signup, no email required. Everything runs instantly and nothing you paste is stored.
Deliverability checker
Check any domain's SPF, DKIM, DMARC, and MX records in seconds.
Spam word checker
Scan a subject line and email body for spam-trigger phrases.
Warmup calculator
Get a day-by-day sending ramp schedule for a new or existing mailbox.
Email HTML checker
Check text-to-HTML ratio, images, links, and tracking pixels in an email.
Which one should you run first?
Start with the deliverability checker: if your domain is missing SPF, DKIM, or DMARC, nothing else you change to the email itself will fix inbox placement. Once authentication passes, run the warmup calculator to work out how fast you can safely ramp a new mailbox, then check the email itself — copy through the spam word checker, markup through the email HTML checker — before you send at volume.
All four run instantly and none of them require an account. The spam word, warmup, and HTML tools run entirely in your browser; the deliverability checker performs a live DNS lookup and stores nothing.
Beyond a one-off check
A checker tells you today. Monitoring tells you when it breaks.
Every tool on this page is a snapshot. DNS records get edited, selectors expire, a registrar migration quietly drops a TXT record — and the next thing you notice is a campaign that stopped replying.
InboxPulse re-runs the same checks daily on every connected mailbox and charts placement per provider, so a change shows up as an alert with a cause attached rather than as a slow, unexplained decline.
Want this checked for you every day?
InboxPulse monitors SPF, DKIM, DMARC, and MX daily and Warmflow automates warmup — so deliverability stays fixed instead of needing a re-check every time something changes.