Email authentication
Check DMARC
How does my domain protect against forged senders?
Check the effective DMARC policy, SPF/DKIM alignment settings and reporting destinations.
Check DMARCCheck your email infrastructure for free
Enter a domain and get findings with explanations, measurements and a useful next step. No account or email address required.
Start with the complete picture
The domain check combines email DNS, authentication and transport policies. Website and blocklist findings appear separately and do not change the email score.
Check a specific question
Choose the area you want to investigate. Each tool explains its scope and shows the full result.
Email authentication
Check SPF
Which senders are authorized, and is the SPF record valid?
Check SPF syntax, mechanisms, dependencies, DNS lookup limits and network ranges.
Check SPF
Mail routing
Check MX and DNS
Where is incoming mail routed, and do the DNS targets resolve?
Check mail routing, target resolution, null MX, DNSSEC and redundancy indicators.
Check MX and DNS
Transport encryption
Check MTA-STS
Does my domain publish a usable policy for encrypted mail transport?
Check the TXT record, safely retrieved HTTPS policy and MX coverage.
Check MTA-STS
Transport reports
Check TLS-RPT
Can senders find where to report transport encryption problems?
Check the TLS-RPT record, reporting URI syntax and DNS evidence.
Check TLS-RPT
Blocklists and reputation
Check blocklists
Are publicly discoverable mail IP addresses on selected blocklists?
Check MX and explicitly discovered SPF sender IP addresses using an approved reputation provider.
Check blocklistsScope of the public checks
The tools use public DNS records and limited HTTPS requests where needed. Blocklists are checked only for mail IP addresses found through MX and SPF. Public tools do not access mailboxes or perform SMTP or port scans.
Module in your Sendequelle account
Explore the account module
Email forensics in your account
Understand headers and message files, trace delivery routes and compare private messages with your own references. Available after signing in to your Sendequelle account.