Technically yes, but it involves a little bit of setup, and some online hosting space. Most appointments can be saved as .ics files, and you can host this file online and link to it from the body of your email. Here's an example of how to do this from outlook; it may look a little different from iCal or another program.
1. Create your appointment
2. From the appointment window, right click on the .ics attachment and choose "Save As"
3. Save your file to your hard drive
4. On your hosting service, (your own website, google docs, etc) upload your file, and check the url.
5. You can now use this url as you would any other link. Recipients who click the link will be invited to download the meeting appointment.
Note: You cannot see accepted or denied invitations using an ics file.
If you're looking to get confirmation for your events, why not check out our events tool!