EHLO – Mail Server Tester

EHLO is the mail tool for everyone who runs mail servers: it checks whether a domain is properly protected against forged senders, tests SMTP servers all the way to a delivered test message, and explains why a message ended up in spam. All in plain language instead of raw data.

CHECK A DOMAIN • MX, SPF, DKIM, DMARC, MTA-STS, TLS reporting and BIMI at a glance, with a rating for each • Every finding in one clear sentence, plus a concrete hint on what to improve • SPF: counts DNS lookups across all “include” entries and warns before the limit of 10 • DKIM: tries the common selectors by itself, and you can enter your own; warns about short or revoked keys • MTA-STS: loads the policy and checks that it covers all mail servers • The DNS records found, verbatim, to copy and share

BLOCKLISTS AND REVERSE DNS • Checks a domain's mail servers and the domain itself against 16 DNS blocklists • Enter an IP address: reverse DNS in both directions and all blocklists for exactly that server • Says so honestly when a list gives no answer through the device's DNS service, instead of reporting “clean”

MONITORING • Have domains and IP addresses checked regularly in the background • Notification when MX, SPF, DKIM, DMARC or MTA-STS change or a server lands on a blocklist • Change log with the state before and after, record by record • A difference is only reported once a second lookup confirms it

SMTP TEST • STARTTLS, implicit TLS or unencrypted, any port • Sign-in with PLAIN, LOGIN, CRAM-MD5 or XOAUTH2 (access token) • Test message with CC, BCC, HTML version, custom headers and attachments • Complete session log with timings, colored and copyable; passwords and tokens never appear in it • Templates for common providers, saved servers with the password in the keychain • History of all tests, searchable by server, recipient and log text

ANALYZE HEADERS • Paste a message's headers: the route from server to server with transit times and delays • SPF, DKIM and DMARC results, encryption of each hop, spam rating • Explains what the findings mean

SECURITY AND PRIVACY • App lock with Face ID, Touch ID or device passcode • Encrypted backup of servers and domains (AES-256) to move to another device • No account, no ads, no tracking. EHLO talks only to the servers you enter and to your device's DNS • Header analysis runs entirely on the device

For iPhone, iPad and Mac, one purchase for all devices. English and German.

Note: on iPhone and iPad the system decides when a background check runs; on the Mac, checks run while EHLO is open. An overdue check is caught up when you open the app.

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