Hi. I would like to serve up an "add to calendar" event for either Google calendar or Outlook based on the recipient's email client. Can this be done using dynamic content? Can somebody point me in the right direction? Thanks!
There's really no way to do this from within an email. In order to determine what email client is opening a piece of mail, you would need to execute script there, which email clients do not allow. The typical way I've seen is to have separate buttons for .ics(add to iCal/Outlook) and Google(Add to Google Calendar. You can generate the ics with a standard calendar token, and this explains how to create a google calendar button: Add a Google calendar to your website - Calendar Help