Free SMTP email connection tester
Quickly test your email client’s SMTP connection abilities using a temporary mail account. Create a new server to begin, then connect with your application and see what it is actually doing in real time.
We’ll show you the raw connection details, and analyze the way your client behaves to help you understand any issues. If you need to test other protocols, we also have free testers for IMAP and POP using the same test credentials.
This tool is free and anonymous, no registration or email required.
Your test SMTP server is ready to use. Set up your email client or app to connect to
No recent activity found – monitoring paused
Need help getting set up? See our client setup guides for links to walkthroughs with common email apps.
What is SMTP?
SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending email. When you click Send in your mail client, it uses SMTP to hand your message to your outgoing mail server, which then forwards it toward the recipient's server. SMTP is used for sending only; to receive mail you use IMAP or POP3.
SMTP with SSL/TLS uses port 465. If you need to test an IMAP or POP3 connection, use our IMAP tester or POP3 tester.
Connection tester help
My client connects but doesn't appear in the log
Click I've set up my client to start monitoring, then trigger a fresh connection from your client. Some clients only connect when you open the app or click Send / Receive.
Authentication failed / login rejected
Double-check that your client is using the exact username and password shown above. The username is a full email address and the password is case-sensitive.
TLS handshake failed or connection refused
Ensure your client is configured for SSL/TLS on port 465. STARTTLS (port 587) is not supported by this tester. If your client uses an older TLS version, try our legacy server.
The server shows a connection but login never succeeds
Your client may be sending credentials in an unsupported format. Check that your client's authentication method is set to Normal password or Plain.
My emails aren't being received
The connection test tools on this page are free to use, but please be aware that no real messages are sent or received outside of the test environment. Attachment contents are removed. Test servers and all data are deleted after one hour.
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