Real-Time Pre-DATA Execution
Debug "Relaying Denied" and authentication errors instantly. We execute a live, step-by-step SMTP test—verifying AUTH LOGIN, MAIL FROM, and RCPT TO—to provide the exact server transcript and pinpoint where your app is rejected, safely halting before actual email delivery.
Is your app failing to send emails through SendGrid, Office365, or Mailgun? Enter your credentials and addresses to simulate a full SMTP transaction. We'll test AUTH LOGIN, MAIL FROM, and RCPT TO to pinpoint exactly where the server rejects you.
Don't blindly guess why your application isn't sending emails. Run a granular test that simulates the exact conversation between your app and the mail server.
AUTH LOGIN command to ensure your credentials are valid.550 Relaying Denied error happens during the RCPT TO phase. We execute this command specifically to see if the server permits you to send to external addresses.MAIL FROM address doesn't exactly match the authenticated username. We catch this error instantly.STARTTLS connection before attempting authentication, ensuring your credentials aren't sent in plaintext.RCPT TO command and then issue a QUIT. We do NOT send an actual email (the DATA command), preventing test spam.Your feedback has been submitted successfully. We appreciate your help in improving our tools.