Before you start
- An authorized sending mailbox or transactional service.
- Its actual settings and an address to receive tests.
Understand what SMTP fixes
WordPress triggers messages after form submissions and password resets. SMTP provides an authenticated transport for those messages. It does not fix a form that never generates an email or guarantee that every recipient places the message in the main inbox.
- Test a simple notification first and record its recipient.
- Distinguish website-generated messages from your personal email application.
- Prepare a sender address on your domain and WordPress administrator access.
Prepare a mailbox or sending service
Create a dedicated mailbox in DirectAdmin or use a transactional service supported by your plugin. A separate account helps limit use of your personal mailbox. Obtain the host, port and encryption settings for this actual account; do not copy another domain's settings.
- Confirm the mailbox exists and its password works through webmail.
- For Microsoft 365 or Google Workspace, use the provider's recommended authentication method, often a dedicated connector.
- Keep SMTP credentials and API keys private; website administrators can access sensitive configuration.
Install an email delivery plugin
In Plugins → Add New Plugin, find WP Mail SMTP and confirm its publisher. Install and activate it. Open WP Mail SMTP → Settings and choose a method suitable for your provider. Only one plugin should control delivery to avoid conflicting settings.
- For a mailbox supporting traditional SMTP authentication, choose “Other SMTP”.
- Enter a sender address authorized by the service and a recognizable name.
- If you force the sender address, check its effect on forms and notifications before finishing.
Enter your account settings
Enter the supplied hostname, then the matching port and encryption mode. Port 465 generally uses implicit TLS, often labelled SSL in plugins; port 587 generally uses STARTTLS. Settings actually supplied for your account take precedence.
- Enable authentication when required and enter the full mailbox username.
- Use an application password when your provider requires it, without reusing another service's password.
- Save the settings. Do not disable certificate verification to bypass an error.
Send a test and check real forms
Use the plugin's tools to send a test email to an address you can check. Verify delivery, spam filtering and sender identity. Then test an actual form and a WordPress notification because their settings may differ.
- For connection failures, check host, port, encryption, username and password.
- If the test arrives but a form does not, check the form notification, recipient and plugin errors.
- Where supported, use the visitor's address as Reply-To rather than as the authenticated SMTP sender.
SMTP testing works, but the form does not
Transport works for that test. Now check whether the form generates a notification, which address it targets and whether an error interrupts that step.
Investigate rejected delivery
Server acceptance is not proof of receipt. Have SPF, DKIM and DMARC checked for the actual sending service. Do not replace DNS settings with generic values. Available logs depend on the plugin and its free or paid edition.
- After changing the mailbox password, update the website's sending configuration.
- Give support the time, error and a test recipient, with unnecessary private information masked.
- For order confirmations, also check WooCommerce email triggers.
Frequently asked questions
Does SMTP guarantee inbox delivery?
No. SMTP authenticates transport. Reputation, DNS and recipient filtering also affect receipt. Test actual delivery.
Official documentation
Labels and options vary with versions, plugins and your account. Refer to publisher documentation for your configuration.