Test an SMTP server and see the entire conversation.
Connect to SendGrid, Mailgun, Amazon SES, GMass, or any SMTP server and watch the exact client/server exchange. It’s a fast way to diagnose authentication, TLS, connection, and sending problems.
SMTP connection details
Enter the same host, credentials, and security settings your application uses. We’ll connect and stream the SMTP exchange below.
See where the SMTP connection actually breaks.
Instead of guessing from a generic “couldn’t send” message, the transcript shows the server responses involved in connecting, authenticating, negotiating security, and sending.
Confirm the hostname and port actually accept an SMTP connection.
Try the exact security mode required by your SMTP provider.
See the SMTP server’s response when the username, password, or auth method is rejected.
Inspect the conversation if the server accepts a connection but rejects the sender, recipient, or message.