@HollySimmons - I’m not sure that you can either. Would love to find out if there are some tricks on this as the options are limited on customizing the look of this button. 

The button may look better if the width is smaller. And you might be able to adjust the width of the email depending on what your HTML looks like. It looks like your email is quite wide based on where the button is currently centered.

There was a similar question to this a year ago (how to center the inline question). This might be a good option for a product idea if neither are currently available. 

Hello @HollySimmons @jean.nairon 
We are redesigning our UI, in which surveys looks bit different. Once i have new designs i can share it here and. collect your inputs.

Thank you for the update @chethana. It’s most appreciated.

Since this is an enhancement request, changing this to idea post.

This is a basic thing, must have ASAP

100% agree with @abhijeetbakare, seems like a standard option for email templates. The button is way too far out of line with the rest of the email and seeing as the button is the call to action item, it should be visually in line with what is said around it.