A short list of tools we find useful for diagnosing and fixing email deliverability, including the ones we build ourselves. Each runs in the browser against your live DNS or a header you paste.
All free, and no signup to see a result. The audit and record checkers hand you the exact record to publish.
Checks MX, SPF, DKIM, DMARC, TLS-RPT, MTA-STS, BIMI and blacklist status, then returns one Email Setup Score and a numbered fix plan.
Validates your SPF record and counts DNS lookups against the limit of 10, then shows the exact record to publish.
Reads your DMARC policy and alignment and shows what to publish to move from none to enforcement.
Checks the eight authentication and transport records inbox providers read before they trust your mail.
Checks whether your sending IP or domain is listed on DNS blacklists, and shows each list result and what to do if you are listed.
Scans a domain for the deliverability risk signals that quietly sink cold outreach.
Paste a raw message header to trace the delivery path and read the SPF, DKIM and DMARC results for that message.
Upload a DMARC aggregate report and read what receivers reported: sending sources, pass and fail counts, and GeoIP enrichment.
Tools from other people that cover similar ground. Listing here is not an endorsement — try them and judge for yourself.
Free weekly DMARC report summaries emailed to you, from the Postmark team.
Email list verification. Checks whether the addresses you are sending to actually exist.
Walks through a live DMARC check step by step. Useful if you are learning how the checks fit together.
A browser-based SPF record checker and generator from the Sidemail team.
A browser-based DMARC record checker and generator from the Sidemail team.