Email HTML Is Twenty Years Behind the Web, on Purpose

The two images, again

The exported file inlines what was inside the message and leaves alone what was not. Images the sender attached and referenced as cid: become part of the file, so they show whether or not you are online, and the page stays self-contained if you copy it to a backup disk. Images the sender left on their own server stay as addresses, so opening the file years later shows gaps where a marketing banner used to be — and, if the server is still running, tells its owner you opened an old message today.

When to prefer HTML, and when text

Take HTML when the appearance is part of what you are keeping: an invoice with a table of lines, a booking confirmation with a reference laid out to be read, a message you may have to show someone as it was received. Take plain text when you want to search, quote or store thousands of messages — text is a tenth of the size and does not carry a layout that will age. Keeping both for the handful that matter costs nothing and settles the question later.

Frequently asked questions

Will the exported page look the same as in my mail client?

Close, and not identical. Your mail client applies its own defaults on top of the message — fonts, spacing, a maximum width — and a browser applies different ones. Since the message carries its styles inline, the substance travels; what shifts is the frame around it. If an exact record matters, print the page to PDF from the browser and keep that alongside.

Why do so many messages still use tables for layout?

Because it is the only layout every reader still renders the same way. Modern layout systems are supported unevenly across mail clients, and a design that collapses in one of the big ones is a design that fails for a share of the audience the sender cannot identify. Tables are ugly to write and they work everywhere, which in email has always been the winning combination.

Is the exported HTML safe to open?

It is the message's own markup, so it carries whatever the sender wrote — which in practice is styles and links, since scripts do not survive the trip through the mail system. Treat the links with the same suspicion you would in the mail client: an exported page has lost the warnings your client was showing around them. If the message was one you distrusted, read it as plain text instead.