To view the email before it's sent from Drupal, especially when using Drupal 10 and dealing with encrypted emails or a specific module like Mailhandler, you can take a few steps to intercept or debug the email before it's actually dispatched. The process involves either configuring your configuration for debugging emails or using a development tool/module that captures outgoing emails.
Use Drupal's Mail System Configuration for Debugging
Drupal allows you to configure the mail system to use a different class for sending emails, which can be handy for debugging. You can switch to a 'null' or 'test' mailer that doesn't actually send the email but logs it or dumps it to the screen.
Install and configure a mail logger module: Modules like Devel or Maillog can be used to log emails instead of sending them. These modules provide options to log all mail sent by Drupal and usually offer a way to view the mail before it's encrypted and sent.
You can write a small module or use a hook_mail_alter() implementation in a custom module to alter or log the email before it's sent. A basic example of how you can log the email details
/**
* Implements hook_mail_alter().
*/
function mymodule_mail_alter(&$message) {
\Drupal::logger('mymodule')->notice('Mail ID: @id, Subject: @subject, Body: @body', [
'@id' => $message['id'],
'@subject' => $message['subject'],
'@body' => is_array($message['body']) ? implode("\n", $message['body']) : $message['body'],
]);
}
Development and Testing Environments
For development and testing purposes, consider configuring your Drupal environment to send emails to a development service like Mailtrap, MailHog, or a similar service. These services capture outgoing emails and allow you to view them in a web interface, including headers, HTML content, and plain text.
Configure SMTP settings: Use the SMTP module to configure Drupal to send emails through a service like Mailtrap. This requires changing SMTP settings in your Drupal configuration to point to your Mailtrap inbox, allowing you to see all emails sent by Drupal in the Mailtrap dashboard.
Use MailHog: MailHog is a local SMTP server designed for development use. It captures emails sent by your Drupal site and makes them available in a web interface. You can run MailHog on your development machine or within your development environment.
Final Steps
After setting up one of the above methods, try triggering an email in your Drupal site that would normally be sent through Mailhandler. You should be able to view the email in the configured logging tool or email capture service before it's encrypted and sent, allowing you to see if there are any formatting issues or additional spaces being added.
Keep in mind that altering the mail system or using development tools like these should only be done in a development or staging environment to avoid disrupting email functionality in your live environment.