Anyone who designs HTML for emails on a constant basis should set up a testing server but for someone like me who only has to create a couple HTML emails, max per web design project, I found Campaign Monitor to be the best free option, hands down. 

They allow as many free test emails as you want – I just set up a free account and within seconds I was putting the email together in an incredibly user-friendly interface (great work, guys). I really enjoy this tool – I can’t say much about their email campaign management features, but I am very impressed with the testing interface so I’m sure it’s great.

They also allow you to test the email in a large selection of email clients (I only really cared about gmail and Outlook but they have pretty much everything), which is obviously a must for large-scale email campaigns.

The Problem With Coding and Sending HTML Emails

You can’t send standards-compliant HTML with a nice stylesheet to structure the layout, you have to use tables, spans, and (sad but true) the font tag.

And of course, the main reason you want to send a HTML email (flyer, newsletter, or whatever) is so that you can send in-line pictures in that email. The problem is, you can’t simply send the images as attachments, you have to actually install them on your server (same server you’re mailing from) and link to them with absolute paths – that’s where testing them becomes extremely inconvenient.