Feature Request: SMTP Email History & Optional IMAP Sent Archiving

Pain point When using standard SMTP, successfully sent emails do not appear in Invoice Ninja's Email History. Additionally, outgoing messages are not saved to the user's IMAP Sent folder. Both are useful features that should not require a transactional email provider such as Mailgun or Postmark. Proposed solution • SMTP Email History: Populate the existing SystemLog history using Laravel's MessageSent event. • IMAP Sent Archiving: Optionally append the original MIME message, including attachments, to a configurable IMAP Sent folder. • Independent operation: IMAP failures must not affect email delivery or history logging. Suggested architecture Implementation sketch (illustrative) Extend the existing MailSentListener: Potentially reuse SystemLog::CATEGORY_MAIL, EVENT_MAIL_SEND and the existing history.events structure. The optional archive job would use IMAP APPEND with the original RFC 5322 message, preserving head…