Download Mailroom

Direct download only — a Microsoft Store install never shows this. Every release is code-signed by Mailroom-LTD, but Windows gives a new publisher's files a low reputation score until enough people have installed them, so you may still see “Windows protected your PC”. Click More info, then Run anyway. If Windows Defender goes further and calls the file a threat, that is a reputation false positive on a new build — we virus-scan every release we publish; check the hash above, then allow the file (step by step).