HTML validated against common email clients

Email clients are notoriously inconsistent renderers — Outlook 2016-2019 strips flexbox and CSS grid, Gmail removes unreferenced <style> blocks, and Apple Mail handles media queries differently from Yahoo. Templates that render perfectly in the preview pane arrive as broken, unstyled blobs for a meaningful portion of recipients, directly degrading conversion on transactional and marketing sends. The user-experience cost compounds for password resets, receipts, and onboarding flows where a misaligned CTA means an abandoned signup or a support ticket.

Adopt MJML for new templates so the compiler emits table-based, client-safe HTML, or pipe existing HTML through a CSS inliner like juice before handing it to the ESP. Wire a Litmus or Email on Acid check into CI against Outlook 2016, Gmail web, and Apple Mail. See src/emails/ for template organization.

import mjml2html from 'mjml'
import juice from 'juice'

const { html, errors } = mjml2html(template)
if (errors.length) throw new Error(errors.map(e => e.formattedMessage).join(', '))
const inlined = juice(html)