It's definitely not possible to use WordPress/s2Member shortcodes in an email, as the email wouldn't have the WordPress framework necessary to turn the shortcode into the form or link that creates the button.
However, taking a step back, if you want to send your customer a link to join the monthly fee membership and you want that to happen with their existing s2Member account, you'll need to figure out how to automatically log them into s2Member/WordPress bypassing their username/password authentication and then send them to a page where they can click on a button to make the purchase (or just send them directly to the checkout page).
Automatic login from a link on an external site/email is not something currently supported by s2Member, so you'd need to find/build a plugin that adds that functionality. From a technical standpoint, it is possible, but it's also messy and prone to security holes.Statistics: Posted by Raam Dev — January 11th, 2012, 12:51 pm
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