Mail Tools

    SPF analysis, builder and flattening, BIMI logo validation, DMARC alignment simulation, and DKIM private-key ↔ DNS-record matching — everything you need to debug email authentication for a domain.

    Looking for a single overall grade? See Deliverability Score. For MTA-STS, TLS-RPT and mail SRV autoconfig, see Advanced Diagnostics.

    Security audits

    DMARC alignment simulator

    Visual SPF builder

    Pick the services that send mail for your domain:

    Microsoft 365
    Google Workspace
    SendGrid
    Mailgun
    Mailchimp
    Amazon SES (eu-west-1)
    Postmark
    Zoho Mail
    MX hosts (a/mx)
    Domain A record
    Default policy:
    -all
    ~all
    ?all
    +all
    Generated record (lookups: 0/10)
    v=spf1 ~all

    DKIM key matcher

    Paste a private key (PKCS#8 PEM) and the corresponding DKIM TXT record. Matching happens locally in your browser — keys are never sent over the network.