About ColdMailCheck
ColdMailCheck is an independent resource for people who send cold email and want it read. The tools are free, run in your browser, and show their working: every domain check returns the raw DNS record, every spam score shows the exact phrases it counted.
The guides are written from running cold email infrastructure, not from summarising other guides. Each one answers a single question in its first paragraph. Numbers are stated with their source or their basis, and updated when mailbox providers change their rules.
How the site is funded
Display advertising, and affiliate links to tools we recommend. Affiliate links are marked on the page where they appear. Recommendations are not for sale; see the disclosure.
Corrections
If a tool gives a wrong result or a guide is out of date, email hello@coldmailcheck.com. We fix errors and note the change on the page.