Is there a risk associated with sending HTML email instead of just plain-text? We alluded to this debate in our guide to welcome emails. There we recommended HTML emails with the stipulation that you should test both. The reason for that stipulation, however, was more about preference than deliverability.

Does Plain-Text Email Really Have 100% Deliverability?

There is no email client in the world that cannot open a plain-text email. So there’s that. But 100% deliverability is a bit misleading. I can assure you there are plenty of plain-text emails in my spam folder right now.

Of course, you’re not sending actual spam emails (you wouldn’t do that, right?), and there are only so many ways you can verify email addresses, so there are really two issues to focus on:

  1. Would my users prefer plain-text?
  2. How do I keep my HTML emails from triggering filters?

Do the People Want Plain-Text?

There are a couple of circumstances where it makes sense to use plain-text as an aesthetic decision. Sometimes you want to follow up with a user in a personal way, while still automating the process for timeliness. Here’s a great example from our friends at Zapier:

Zapier activation drip

Even simple emails like this, though, often contain a bit of HTML – either for formatting links or to load a tracking pixel. But no email filter is going to use the existence of that small amount of code in and of itself as a reason to flag the email as spam. Derek Halpern wrote a great post on testing what he called “simple vs. fancy” for the mailing list at DIYThemes.

So do you want simple or fancy?

Fancy, Obviously – But How to Do Fancy, Not Flagged?

The short version is pretty simple: write like an adult human. Ask yourself, “Would this look at home on a Geocities page circa 1997?” And go from there. Scrolling text, word-art, code generated from Microsoft Word, brightly colored text,  all caps, tons of exclamation points – any of these things can get you targeted by an email filter and, frankly, they should. Nobody wants to see that.

Include a Plain-Text Alternative

Most template managers allow you to generate and include a plain-text version of the email. This is generally a good idea. In our editor, it’s just a couple of clicks away:

generating a plain-text version in sendwithus

Mind the Plain-Text Preview

Most email clients will pull the first text outside of a tag and use it for a preview of the email.

don't forget a plain text preview

A lot of templates include a dedicated space for this preview text, known as the preheader, and it’s often populated with placeholder copy. If you’re using such a template, please, for the sake of your user’s sanity, replace the placeholder text! None of your customers want to see an email in their inbox with preview text that says, “Insert preview text here.”

plain text header left blank

Don’t Overuse Images

Last December, Gmail made the switch to automatically display images in emails (this was always an option, it just wasn’t the default). This increased their capacity to display images through their proxies, NOT an invitation to turn entire emails into images.

A high image-to-text ratio is the most common cause of false positives in spam filters. Consider using an HTML button from our library of bulletproof email components. They’re more responsive, they look nicer, and they help keep that ratio in check.

Don’t Send Broken Code

This is just common sense but you’d be surprised how often it happens. Always – always – check your code. Within both Dyspatch and Sendwithus, we use Litmus for device testing, to make sure an email renders properly on all email clients and devices, or at the very least, on those your customers use most.

Don’t Come on Too Strong

RL Spam

Don’t be like this guy

If you didn’t grow up with commercials like the one above, they’re basically TV spam. The bottom line is that there are just some things that are never going to be legitimate and “Free Money” is certainly one of them. In general, it’s a good idea to avoid the language common to this kind of promotion.

There’s a great entry on HubSpot with a big collection of these trigger words. It’s a bit out of date – “free”, for example, is no longer the huge trigger it once was – but it’s still helpful. A good rule of thumb, though, is to just avoid making any kind of hyperbolic claim – anything you might see on a bus stop bench or tacky billboard could put you in the danger zone.