# SMTP Test Tool

URL: https://dev.symelo.com/bg/tools/smtp-test

Test an SMTP server's connection, TLS and login, and send a test email while reading the full SMTP conversation.

## Usage

1. Enter the SMTP host, choose the port and encryption: STARTTLS for 587, 25 and 2525, or SSL/TLS for 465.
2. Add a login if the server needs one. To send a test email, fill in the sender, recipient, subject and message.
3. Choose Test connection or Send test email, then read each step's result, the TLS certificate details and the full SMTP conversation.

## Behavior

- Tests run from Symelo's server, so the SMTP server must be reachable from the public internet. Private and reserved addresses are refused. Ports 25, 465, 587 and 2525 are supported.
- Passwords are used for one test and are never stored or shown in the log. Logins require STARTTLS or SSL/TLS.
- Each test sends at most one email to one recipient. Without a login, the recipient's domain must receive its mail on the tested server. A recipient gets at most three test emails an hour.
- This tool has no public HTTP API.

## Related pages

- [All tools](https://dev.symelo.com/bg/tools)
- [Agent documentation](https://dev.symelo.com/llms.txt)