Event invitation response emails
A co-worker created a test event in his calendar (on a non-Zoho system) and sent me an invitation by email. I accepted the invitation in my email client (Thunderbird) and it properly added it to my Zoho calendar. However, he never got a response, indicating that I had accepted it. We run our own mail server so I was able to check and see that there was no incoming mail from zoho(anything).com to him, nor was there one sent from my email address.
This is kind of important, letting people using other calendaring systems (i.e. outside our small company) know whether you've accepted an invitation or not. There doesn't seem to be a switch in Thunderbird for this; is there one somewhere in Zoho? How do I generate an email response confirming I'll attend an event I'm invited to by a non-zoho calendar user?
The FAQ deals with the case of inviting outsiders to events on a Zoho calendar:
https://www.zoho.com/calendar/faq.html
but not the case of BEING invited to events by non-Zoho users.