lonnieezell/postal — reverse-engineered prompt

Build me a modern email library for CodeIgniter 4 called Postal. I want it to replace the built in Email class with a cleaner system where I can write an email once and choose how it gets sent from config instead of changing app code.

It should support SMTP, Sendmail, PHP mail, log, null, and fake testing transports for now. Keep the old CodeIgniter style service email calls working so existing apps can migrate without rewriting everything. Also add a newer mailer service where I can create Email objects, set from, to, subject, html or text content, and get back a clear send result with success, message id, error, and raw response.

Please include reusable Mailable classes, events around composing, sending, sent, failed, and suppressed messages, and a fake mailer with useful PHPUnit assertions so tests never send real email.

Use PHP 8.2 and CodeIgniter 4.7 conventions. Add docs, config examples, commands like making a mailable and sending a test email, and make sure the test suite and static checks pass.