TechniquesConvertconvert

Checking the HTML, not the preview

A preview renders your mistakes exactly as faithfully as your design.

Why it works

A preview shows what the HTML says, and so does the inbox.

If the HTML is wrong, both show the same wrong thing.

You are looking at the layout while the two real problems sit in the source.

Use it when
Before every send, which is the point.
Skip it when
Your platform already blocks a send on these. Few do.
What to watch
Unfilled merge tags and any link pointing somewhere only you can reach.
What it costs you
Two seconds, and the discipline to do it when you are late.

Put your own numbers in

There is no figure here for what this does. Nobody knows what it does on your list.

Pre-send Check

Also in Convert

Measure it before you build it.

Pre-send Check runs on your own numbers. Free, no account, and nothing you type leaves your browser.