MarketingSherpa has an Open Access article about the large percent of subject lines that are arriving in your clients' inbox with “broken code”:
Jun 12, 2007
How To #:
Exclusive: New Research Shows 53% of Email Subject Lines Broken + How to Fix Yours
The #1 culprit for the broken code, once again, is Microsoft Word. Seems lots of you out there like writing things first in Word, then cutting and pasting into the email.
I personally recommend never writing anything in Word that is meant for another program, especially HMTL! See what people don't know is that Word has its own rendering engine. (To understand a little more about Rendering Engines visit wikipedia's page on the subject).
If you really want to write an email subject line or the entire body of the email, not to mention a blog entry or content for a web page, please use a program like NotePad or TextEdit.
Now, getting back to the subject line of this blog entry, when you are sending out email campaigns make sure you do two things:
1. Type (do not cut and paste) into the subject line
2. Test the email first, before sending it out to the world
I always test on both Mac and PC, in as many email clients as possible (Yahoo, Hotmail, AOL), on as many browsers as possible (Internet Explore, Safari, and my favorite Firefox).
Yep, that is a lot of extra work, but it helps to be sure that most people are going to see your email campaign the way you intended – subject line and all!