This is How Email Calendar Event Invites Work

Ever curious how calendly,, and Meetup send you an email that integrates seamlessly with your email? Wonder no more! I break it down for you in this article.

Photo by Towfiqu barbhuiya on Unsplash

High Level View

At a 30,000-foot level view, a .ics file is generated, and sent as an attachment to your email. Within the ICS are other event members, such as the organizer. This becomes important later.

The Email Attachment

This is the meat 🥩 and potatoes 🥔 of the system (or tofu and kale if you prefer). You can even investigate it yourself. Open up an email for a recent event invitation and check out the contents. Here’s an example of mine (sorry, cyber criminals, I removed anything sensitive):


SUMMARY:John Doe and Jane Smith
DESCRIPTION:This is a description of an example meeting\n
There are even multiple lines

The Email Exchange

This ICS file is all well and good, but it’s just sitting on the server not doing anybody any good. How does it get out to the other participants?

There you Have It!

Mystery solved! Now you know how systems like Calendly and (the better alternative) Ink-In-Time work.



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store