Unlock this challenge:
What happens if you add a tag and metadata to an email but your Mailer transport doesn't support them?
The tags and metadata will be added as generic headers (X-Tag and X-Metadata).
X-Tag
X-Metadata
The tags and metadata will be ignored and not included in the email.
The email will fail to send, and you’ll receive an error message.
The email will be sent with the tags and metadata as custom HTML content.
