HTML Email Template Generator

Many email clients - notably Microsoft Outlook on Windows - render messages with the Word engine, which has very limited CSS support and ignores flexbox, grid, and most positioning rules. Nested HTML tables remain the only layout system that renders predictably across the full mix of clients, including Gmail, Outlook, Apple Mail, Yahoo and mobile webmail. That is why production email HTML still looks like web markup from 2003: it is the lowest common denominator that survives every rendering engine.

MSO conditionals are HTML comments that only Microsoft Outlook (Word engine) parses. They look like <!--[if mso]> ... <![endif]--> and let you ship markup or styles targeted specifically at Outlook without affecting other clients. They are commonly used to set a fixed container width with a ghost table, fix VML for buttons and backgrounds, and disable features that Outlook renders incorrectly. Without them, layouts often collapse or stretch awkwardly in Outlook even when they look perfect everywhere else.

Several major email clients - historically Gmail in particular - strip out <style> blocks or apply them inconsistently, especially on mobile and in forwarded messages. Inlining moves each rule onto the element it targets via the style attribute, which every client respects. The trade-off is verbosity and harder maintenance, which is why tooling - including this generator - exists to inline styles automatically from a higher-level template.

The preheader is the short snippet of text shown after the subject line in most inbox previews. By default it is pulled from the first visible text in the email body, which is often a salutation or boilerplate that wastes the slot. Including a hidden preheader element at the top of the HTML lets you control exactly what appears there. A well-written preheader complements the subject line and is correlated with higher open rates in most A/B tests run by major ESPs.