I got the HTML email button code from: https://gist.github.com/elidickinson/9424116 instead of generating it on buttons.cm
And here is a snapshot of my code: https://litmus.com/builder/4d3209e

The two issues I am having is one, when I preview in Office365 and Outlook.com, the text inside the button is not centered. I don't know how to fix that. And the second issue is getting inconsistent results in Outlook 2000-2007. Sometimes when I refresh the code, <![if !mso]> and <![endif]> will pop up around the button. How do I get rid of it and why is the result inconsistent?