Testing, testing… 1. 2. 3.

Once you’ve built your email, it’s crucial to test it before sending. If you’re lucky, you have a QA specialist on your team to make sure all links are going to the right landing pages and that you don’t have any extra “r”s in the word “cart.”

If not, you just have to be extra vigilant when checking your email. A preflight checklist like this one from Campaign Monitor is a good way to make sure you don’t miss anything.

Send test emails

With upwards of 15,000 possible renderings, it’s important to check an email on as many platforms as possible before sending the real thing. Viewing the HTML file in your browser or editor works during initial development, but you can’t be sure how it will appear to your users without test sends.

If you don’t have the option to send preview emails through your ESP, you can use a service such as PutsMail to send test emails.

PutsMail platform

When I started, I set up a new email account on Yahoo, Outlook, Gmail, Apple Mail, and AOL just for testing (yes, even AOL), and made sure to check each account in the corresponding desktop, webmail, and mobile app versions. (Please note: There are more efficient ways to do this. See next section).

Preview tools

A preview tool such as Litmus or Email on Acid saves you the hassle of sending and checking a million emails.

While you may still want to test the final version email with a few real clients and devices, a preview tool is far more efficient during the build process. It’s also more comprehensive, since it would be virtually impossible to send and view test emails on every available client, operating system, and device that your readers will use.

Which email clients to test

When deciding how much effort to put into coding for any particular client, it’s helpful to know what percentage of your audience is using which clients. Every audience is different, so if you have access to this data, definitely take advantage of it.

If not, Litmus puts out a list of the overall market share for email clients each year, so you can at least have a general idea of where your priorities should be.