SPF checker
Validates the SPF record, follows every include and redirect, counts DNS lookups against the limit of 10, and flags +all, ?all, void lookups and deprecated ptr.
DKIM checker
Looks up a DKIM key by selector, or scans the default selectors of every major mail provider. Key type, size and fingerprint, CNAME delegation, the owning provider and every RFC 6376/8301/8463 defect, with the corrected record.
DKIM signature validator
Paste a raw email. Each DKIM-Signature (up to ten) is verified again from scratch: body hash, RSA or Ed25519 signature, the published key, and alignment with the From domain.
DKIM key generator
Creates an RSA or Ed25519 key pair and the exact TXT record to publish. Keys are generated in your browser; the private key never reaches us.
Email header analyzer
Paste a message's headers. Every Received hop with its delay, SPF, DKIM, DMARC and ARC results per receiver, From vs Return-Path and DKIM alignment, and spam-filter verdicts. Nothing is stored.
DMARC checker
Parses the DMARC record, validates every tag, and explains what the policy actually does to spoofed mail.
DMARC report analyzer
Upload one aggregate report (.xml, .xml.gz, .zip or .eml). See every source sending as your domain, what passes, and why each failing source does not align. Processed and discarded, never stored.
MX lookup
Lists mail exchangers by priority with their IPs and identifies the mail provider.
MTA-STS checker
Reads the _mta-sts TXT record, fetches the policy file over HTTPS, and confirms every MX host is covered.
MTA-STS record generator
Builds the _mta-sts TXT record, the policy file from your live MX hosts and the TLS-RPT record, exactly as published, and shows what changes against what you serve today.
TLS-RPT checker
Validates the _smtp._tls record and its reporting address.
BIMI checker
Validates the BIMI record, logo URL and certificate tag, and checks the DMARC prerequisites for logo display.
Blacklist check
Checks an IPv4 address (or the IPs behind a domain and its MX) against Spamhaus ZEN, SpamCop, Barracuda, PSBL and UCEPROTECT.
Reverse DNS (PTR) check
Finds the PTR record for an IP and confirms it resolves back (forward-confirmed reverse DNS).
Email address check
Syntax, MX, provider, free/disposable/role flags, the domain's sender policy strength and a risk score with reasons.
DMARC record generator
Builds a correct DMARC record from plain-language choices. Copy the host and value into your DNS.
SPF record generator
Builds an SPF record from the services you send with. Exact include values, nothing guessed.