SMTP connection tester
Test a domain's public mail exchanger for an SMTP greeting on port 25.
Inputs are sent to our server to run this check. They are not included in usage analytics.
Your result
Add your inputs, or try the example, to see your result here.
No email is sent. This checks connectivity from this server, not mailbox existence or delivery.
How to use this tool
- Resolve the domain's highest-priority mail exchanger and its public IPv4 addresses.
- Connect to one vetted address on port 25, read the greeting, send EHLO and close with QUIT.
What the result tells you
- No email is sent. This checks connectivity from this server, not mailbox existence or delivery.
- Timeouts may reflect an outbound port restriction, firewall, IPv4 availability or server policy. TLS and login are not tested.