Multipart/alternative is a MIME format that includes both HTML and plain-text versions of an email. Learn why it improves compatibility and deliverability.
Multipart/alternative is a MIME structure that includes multiple versions of the same content, usually plain text and HTML. Email clients can choose the best version to display based on capability and user settings.
This format improves compatibility because some inboxes block images or prefer plain text for security or accessibility. It also helps deliverability and user experience by providing a readable fallback.
A best practice is to ensure the plain-text version is genuinely useful, not a broken or empty placeholder. Keep links readable in text form and avoid stuffing it with tracking junk.