Send email with SMTP

Use Prontuno SMTP credentials with any application, framework, or service that supports authenticated SMTP.

Connection settings

Host	smtp.prontuno.net
Recommended port	587 with STARTTLS
Other supported ports	25, 465, and 2525
Authentication	Required
Username	The SMTP Username generated by Prontuno
Password	The SMTP Password generated by Prontuno
Encryption	SSL/TLS or STARTTLS

Use port 587 with STARTTLS when your application supports it. Port 2525 is a useful alternative when a hosting provider blocks standard SMTP ports.

Create an SMTP credential

1. Verify a sending domain.
2. Open SMTP Credentials in Prontuno.
3. Select New SMTP Credential.
4. Give it a descriptive name, such as Production web app.
5. Choose the verified domain and confirm with your account password.
6. Copy the generated username and password.

Copy the password now

The password is displayed only when it is created or reset. If it is lost, reset the credential and update every application that uses it.

Example environment configuration

Use the variable names expected by your framework or mail library. A common configuration looks like this:

MAIL_MAILER=smtp
MAIL_HOST=smtp.prontuno.net
MAIL_PORT=587
MAIL_USERNAME=YOUR_PRONTUNO_SMTP_USERNAME
MAIL_PASSWORD=YOUR_PRONTUNO_SMTP_PASSWORD
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS=notifications@example.com
MAIL_FROM_NAME="Example App"

Do not commit the real username or password to your repository.

Message requirements

• The From address must use the verified domain attached to the SMTP credential.
• Use a real address that identifies your application or service.
• Send only transactional messages related to a user’s action, account, purchase, or service.
• Use a valid recipient address and a non-empty subject.
• Keep one credential per application or environment so it can be rotated independently.

Test the connection

1. Send a test message to an inbox you control.
2. Open Emails in Prontuno.
3. Search for the subject or recipient.
4. Open the message to inspect its status and event timestamps.

The Last Used value on the SMTP Credentials page updates after a successful login and can help confirm which credential an application is using.

Common SMTP errors

Problem	What to check
Connection timeout	Confirm the host and port. Try port 587 or 2525 and check whether your host blocks outbound SMTP.
TLS or certificate error	Enable STARTTLS on port 587, update the server’s certificate store, and do not disable certificate verification.
Authentication failed	Use the generated SMTP username, not your Prontuno login email. Reset the credential if the password is unknown.
Sender rejected	Make sure the From address uses the verified domain bound to this credential.
Credential disabled	Check its status in Prontuno and confirm that sending is enabled for the domain and team.

Next steps

For delivery issues, see Troubleshoot sending and delivery.