feat(email): implement EmailSendJob class for robust email delivery with retry logic and MX record resolution feat(mail): restructure mail module exports for simplified access to core and delivery functionalities
- Implement CMD-03 tests for RCPT TO command, validating recipient addresses, handling multiple recipients, and enforcing command sequence. - Implement CMD-04 tests for DATA command, ensuring proper email content transmission, handling of dot-stuffing, large messages, and correct command sequence. - Implement CMD-13 tests for QUIT command, verifying graceful connection termination and idempotency. - Implement CM-01 tests for TLS connections, including STARTTLS capability and direct TLS connections. - Implement EP-01 tests for basic email sending, covering complete SMTP transaction flow, MIME attachments, HTML emails, custom headers, and minimal emails.
