Email can be tricky. I’ve previously written about the dos and don’ts of sending marketing emails, but not about the different email formats you can use.

This goes for any type of email you send, whether:

There are three different types/formats of email, and each has its pros, cons and best use case:

  1. Plain text
  2. Rich text
  3. HTML

Plain text email

Plain text emails are just that – plain old text. No formatting, nothing. You could use Markdown to give your text some meaning (lists, emphasis, etc.) and you can be sure that copying and pasting the text will always be reliable.

Unfortunately, it looks a bit boring. You’re limited to one font, you can’t make text bold or italic – pretty unglamorous! And, in general, people are used to emails looking a little bit prettier.

So, while I’m a big fan of writing in plain text, I prefer to stick to rich text for my day to day emails.

Rich text email

Rich text emails are a kind of half-way house. They allow you to make text bold and italic, you can change the colour of text, resize it, and so on. You’re even able to change the font you’re using, though this comes with its own limitations: the font you choose has to be available on the recipient’s computer or they’ll get a fall-back chosen by their machine.

A quick aside: just because you can doesn’t mean you should. There’s nothing worse that receiving an email written in Comic Sans. Well, maybe sending an email written in Comic Sans…

Err on the side of default. Out of the box, most email programs and operating systems use a black ‘sans-serif’ font (the type without little kicks and flicks) in a fairly legible size. This is perfectly fine, as far as I’m concerned.

Limitations include the lack of control over backgrounds, links have to be pasted straight into the email you go see the full URL on the page (like and, like plain text, images are sent as attachments, which can be a bit clunky.

Copying and pasting rich text emails from one app/program to another, or even one email to another inside the same program, is often pretty messy. My biggest bug-bear is when I’m copying and pasting a nicely formatted bulleted or numbered lists – they never seem to make the journey from one email to the other in one piece! There’s always some deleting and re-formatting to do.

But this format is pretty much the standard for conversational emails.

HTML email

HTML email is by far the most flexible format: you can have a header, a footer, background colours, and logos and other images can appear right there on the email instead of as attachments. Just like a website (sort of)!

Sounds great, doesn’t it!? The big downside is that HTML emails require a lot of coding and even more testing to make sure they’ll work properly in your recipient’s email program.

Because of this, these are rarely a good idea for conversational emails – things get really messy as the email is replied to and forwarded on. And getting the formatting into your email program in the first place is often a painful process. Best avoided.

Where they excel, however, is single use emails.

Transactional emails are a good example of single use emails: password resets, account sign-ups, order confirmations and so on. You can have your logo in a properly styled-up header, your contact details in the footer, and the message presented beautifully in between.

Group/marketing emails are an ideal place to use HTML email. In fact, if you sent a plain or rich text email to your mailing list, some eyebrows will be raised.

Like transactional emails, you’ll probably want a header with your logo and strap line, a footer. You can do all sorts of great stuff with your main content – a perfectly designed message with images and website-style links, a strong call to action button at the bottom; pretty much anything you like!


You might think that poor old plain text emails are not worth bothering about, seeing as all of the use cases (conversational, transactional and marketing) are covered by the nicer-looking rich text and HTML.

But HTML and email apps/programs can sometimes be a bit of an unpredictable mix… Sometimes HTML emails aren’t able to be received by the recipient. In some contexts an HTML email can be rejected, and some email programs just don’t like HTML email at all!

For this reason, it’s always a good idea to write a plain text fall-back for your email, so that your recipient always gets your hard-written content.

For group/marketing emails, any email sending service worth its salt will automatically generate a plain text fall-back email, so if the HTML email fails, the plain text version will definitely get through. You’ll probably be able to edit this, so make sure you check it before sending and do some tidying up:

So now you know

I hope that sheds some light on each of the email formats available to you, their limitations and strengths, and where best to employ each.