SMTP connection tester

Test your SMTP server and credentials live to confirm your mailbox can actually send mail before you launch a campaign.

Free · No signup · Runs in your browser

SMTP / credentialsconnectfig.

SMTP hostPort

From emailUsernamePassword / app passwordEncryption

Credentials are used once for the test and never stored.

SMTP / resultstatusfig.

Enter your SMTP details and run the test to validate the connection.

About SMTP

Get sending right

SMTP is the protocol that sends your email. If it's misconfigured, nothing leaves the building.

Use 587 with STARTTLS or 465 with SSL/TLS. Mismatched port and encryption is the #1 failure.

Providers like Gmail require an app password (not your login) when 2FA is on.

FAQ4 entries

Still curious? Our team responds in under an hour.

It connects to your SMTP host on the given port, negotiates encryption, and authenticates with your credentials — confirming the mailbox can send.

Port 587 with STARTTLS is standard. Port 465 uses implicit SSL/TLS. Match the encryption setting to the port your provider expects.

Usually a wrong password (use an app password with 2FA), an incorrect host/port, or the provider blocking external SMTP access.

No. Credentials are used once to run the live test and are never saved.

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