SMTP Tester

Server Configuration

Quick Presets

Gmail Outlook / 365 Yahoo Zoho Mail SendGrid Mailgun Amazon SES Mailtrap

SMTP Host *

Port *

Username *

Password *

Security & Options

TLS / STARTTLS Upgrade connection to encrypted TLS

SSL Connect using implicit SSL (port 465)

Authentication Use username and password to authenticate

Ignore Certificate Errors Skip TLS certificate validation (self-signed certs)

Connection Timeout (seconds)

Auth Method

Email Message

From Address *

From Name

To Address *

Reply-To

Subject *

Content Type

Message Body

Custom Headers (one per line, Header: Value)

Connection Log

Logs will appear here when you send a test email

How it works: This tool connects directly to the SMTP server via PHP sockets and performs real SMTP handshake, authentication, and message delivery. For Gmail, use an App Password (not your regular password). For SendGrid/Mailgun, use your API key as the password. Ensure your server allows outbound connections on the SMTP port.