Using conditional comments you can target different versions of the email outlook client and include your client specific HTML.
Outlook HTML codes
Outlook 2007 and 2010 can be a little tricky when it comes to stacking tables side by side or top to bottom, where you may see some undesired gaps between your tables.
Outlook 2007 – 2013 ignores margin and padding CSS styling when placed within an image.
The Outlook email clients add a spacing above and below images which have a height smaller than 19 pixels.
Some email clients and webmail services such as AOL Mail, Gmail, Lotus, Outlook, Thunderbird, and Windows Mail will display a blue or black border around images that are linked but don’t have a border specified.