Issue: We have a request from our Education department to send our customers an email reminder when we book a new Event with them. We have a large no-show problem with customers forgetting about their booked events with us and are hoping to solve some of it by sending them an email reminder as soon as the event is booked. Inside of this email we would like to embed functionality to automatically add the Event to their calendar via a simple "Add to Calendar" link. Ideally we'd like to support all Calendars, but at a bare minimum we want to support Outlook, iCalendar, and Google Calendar.
From my research, I've determined that Google Calendar seems easiest - Google supports URL parameters that allow me to just pass in Event specific details using merge fields into the URL which brings up a new window for that event to be saved to the Google Calendar.
Problem: Outlook and iCalendar however are not as simple as Google, apparently. It looks like they both support the .ics file format (the universal Calendar Event file type), but neither of them have a URL available that I can pass parameters to. From the research I've done (Here) and (Here) it appears that the only approach to handling the creation of these .ics files is to have a PHP page that serves an .ics file via the text/Calendar mimetype and a bunch of different data points for the Event - resulting in the php page serving a downloadable .ics to then be opened in another application.
<head> of the page which doesn't work with email clients.
Question: So ultimately my question is - can this be done within Email Alerts/Visualforce Pages/Apex without the need for an external PHP page? Or will I need to have our marketing/web team create a PHP page that is capable of receiving parameters, interpreting them, and outputting a correct .ics? I'm looking to solve this problem without apps, but welcome any and all suggestions.