Centering the image

Corey, thank you so much for developing the plugin.

I am trying to center the featured image into my rss.

I’m not sure which code to use, I’m still learning, but using this below:

<span style="color: rgb(58, 58, 58); font-family: 'Helvetica Neue', Arial, Helvetica, sans-serif; font-size: 16px; font-weight: bold; line-height: 21px; text-align: -webkit-auto; background-color: rgb(249, 249, 249); img align='center';">*|RSSITEM:IMAGE|*</span><br />

I do not know what to place to align the image, if this is even possible.
Is this correct? Mail chimp could not help me….
img align=’center’;
within the span style, or do I make another span within the *|RSSITEM:IMAGE|*

Please advise, thank you again,
Heather

for website: http://www.sarahdavidson.com

http://wordpress.org/plugins/add-featured-image-to-rss-feed/