SMTP Troubleshooting
Diagnose common outgoing email problems.
Test fails immediately
Recheck the SMTP hostname, port, username and password.
Connection timeout
A firewall or hosting provider may block outbound SMTP connections. Ask the host whether the selected SMTP port is allowed.
Authentication error
Confirm the provider allows SMTP authentication. Some services require an app-specific password rather than the normal account password.
Message sent but not received
Check Spam/Junk, sender-domain authentication and the recipient address.
Slow sending
Network SMTP connections can take several seconds. The exact behavior depends on the mail server and hosting environment.
Useful error details
When troubleshooting, note whether the failure is a timeout, authentication rejection, certificate/security error or successful send with no delivery. These point to different causes.
For example, a timeout often suggests connectivity or port blocking, while an authentication error usually means the server was reached but rejected the credentials.