Features
SMTP and authentication testing
See exactly what a receiving server sees.
Connect to any public mail server and read the whole conversation, or send one message to your private test inbox and get a graded report on authentication and hygiene.
What you get
The full session, line by line
Greeting, capabilities, STARTTLS, login result and timings for every step, in a transcript you can copy.
TLS you can read
Protocol, cipher, certificate names, issuer, expiry and whether the chain and host name check out.
A private test inbox
Send from your own server to a unique address. We grade SPF, DKIM, DMARC, alignment, headers and reverse DNS.
Your own recipients only
A test message goes only to your test inbox or to an address you have proven you own. Nothing else is ever sent.
Run from clean network locations
Tests start from our own probe network, so a result reflects what the wider internet sees.
Fix suggestions, not just red marks
Each failed check says what to change and shows the exact record or setting.
How it works
- 01
Point it at your server
Enter host and port, and optionally a login. Credentials are used for the test and not kept.
- 02
Watch it run live
The transcript fills in as the test proceeds, usually in seconds.
- 03
Read the report
A pass, warning or fail for each item, with the fix beside it.
Questions
Do you send test email to arbitrary addresses?
No. Messages go only to your test inbox or to a recipient you have verified by clicking a link we send them.
Are my SMTP passwords stored?
A password you type for a one-off test is used for that connection only. Saved accounts are encrypted and can be viewed only inside our workers.
Which ports can I test?
25, 465, 587 and 2525.
Other areas: Blacklist monitoring, Email validation, DNS authentication, PowerMTA servers, Deliverability analytics.
Start with the free plan
No payment details needed. Connect a server, check a domain and see what the tools tell you.