If your subscribers sit in an office somewhere, theyre very likely to use it. Considering its been around at least since 1997, Microsoft has had plenty of time to improve its product, and by many measures has done so.
However, and this is a big one given Outlooks purpose, HTML rendering in Outlook stinks. Outlook 2003 uses Internet Explorer 6 to render HTML, which is pretty bad by modern standards.
As if that wasnt bad enough, Outlook 2007 & 2010 render HTML using Word (yes, the word processor), which is an oil-tanker of offal come to dump its cargo full of torment on your day. If youre an email marketer, email designer, or find yourself in the B2B client space, youve probably encountered some form of Outlook error. Your email looks pristine on your shiny iPhone, Android device, or web-based email client, (and most other email clients) but suddenly blows up when you open it up in Outlook. Yep been there, lets see if we cant help resolve some of the headaches.
Firstly a couple of provisos.
Now that weve cleared that up, lets move on to the good stuff.
Background Images
Put simply, Outlook wont display them at all. If you use a repeating background image, keep it fairly simple and apply a background color as a backup. This is essential to keep HTML text displaying legibly.
Animated GIFs
Outlook will freeze an animated .gif on its first frame. (A shame I know). So keep it safe and avoind animated gifs if you can or if it must be make sure the first frame is relevant.
CSS
CSS code displayed with the <head> tag can display erratically or not-at-all in many email clients, but its particularly nasty in Outlook. Keep your CSS styling in-line.
There are a number of bugs and errors in Outlook, and new ones are encountered with some frequency. So while these are by no means all of Outlooks bugs, heres a look at Outlooks greatest (or worst)
If youve read all the way down here, you may be a bit depressed by now. On the other hand, if youve been coding emails for a bit, youve probably internalized your rage and learned to expect the worst. The solution, simply, is to test, test, and test again. Testing for rendering issues is the only way to make sure your emails render consistently. Always send a test email to an inbox running Outlook.
The second solution is to fill your emails with useful content. Get feedback from your customers on what kinds of messages they want to read and email accordingly. Ultimately, useful content will trump a few graphic discrepancies any day of the week.
Read Microsofts guide to CSS support in Outlook 2007. The best part of this guide may be the comments section, where email designers have contributed a litany of woes.