Email & deliverability tools
Check SPF, DKIM, DMARC, BIMI, MTA-STS, MX, blacklists, and raw headers.
Confirm your brand logo and VMC are published for inbox display.
Blacklist checkerSee if a domain or IP is on major email blacklists.
DKIM checkerLook up a DKIM key by selector and confirm it's published correctly.
DMARC checkerRead your domain's DMARC policy, alignment, and reporting addresses.
Email auth checkerCheck a domain's SPF, DMARC, MX, and (optionally) DKIM records.
Email header analyzerPaste raw headers to map delivery hops, delays, and SPF/DKIM/DMARC results.
Email verifierCheck an address's syntax and that its domain can actually receive mail.
MTA-STS checkerValidate your MTA-STS DNS record and policy file for enforced TLS mail.
MX & SMTP testList a domain's mail servers and confirm the primary answers on SMTP.
SMTP diagnosticsCheck a mail server's banner, STARTTLS support, and open-relay exposure.
SPF checkerExpand your sending sources, validate syntax, and count DNS lookups.
TLS-RPT lookupConfirm your SMTP TLS reporting record is set correctly.
Getting email into the inbox depends on a stack of records and servers all staying healthy — SPF, DKIM, and DMARC for authentication, MX and SMTP for delivery, and a clean sending reputation. These free email deliverability tools let you validate each piece, analyze a raw message's headers to see exactly how it was handled, and confirm you are not on a blacklist. Check anything on demand, and let SJ Monitor watch your email DNS records and blacklist status continuously so a silent change never quietly tanks your deliverability.
Frequently asked questions
Why are my emails landing in spam?
The usual culprits are missing or misconfigured SPF, DKIM, or DMARC, a poor sending reputation, or a blacklisted IP. These tools let you check each in turn.
Can SJ Monitor watch my email setup?
Yes. It can continuously monitor your SPF/DKIM/DMARC and MX records plus your blacklist status, and alert you the moment something changes.
In what order should I set up email authentication?
Publish SPF and DKIM first so your mail authenticates, then add DMARC at p=none to gather reports, and tighten toward quarantine or reject once the reports look clean. Add MTA-STS, TLS-RPT, and BIMI later for transport security and branding.
Do Gmail and Yahoo really require these records now?
Yes. Both require SPF, DKIM, and a published DMARC record for bulk senders, along with low spam rates and one-click unsubscribe. Missing any of these can push mail to spam or get it rejected outright.
What's the fastest way to find why a specific message failed?
Paste its raw headers into the email header analyzer — it shows the delivery path, delays, and the exact SPF, DKIM, and DMARC results the receiver recorded for that message.
Other tool categories
Want any of this watched around the clock? Turn on SJ Monitor's email-record & blacklist monitoring — create a free account and we'll alert you the moment something changes.