Zoho Calendar notification email isn't suppressed

[RussianCow]

Issue Summary

When events are added to Zoho Calendar through the official integration and confirmation emails are enabled in Cal, two emails are sent: one from Cal and one from Zoho. The Zoho email is redundant; I would expect only a Cal email to be sent.

I'm happy to open a pull request for this if it sounds reasonable. The fix seems pretty straightforward.

Steps to Reproduce

1. Install the Zoho Calendar app and set it up such that new bookings are saved to a Zoho calendar.
2. Book an event.

Actual Results

• You receive two emails: a confirmation email from Cal and an event invite from Zoho.

Expected Results

• You only receive the confirmation email from the Cal platform.

Technical details

I only tested on Cal.com, so I'm assuming that the Zoho integration in Cal.diy is the same. My apologies if that is not the case.

In digging into why this happens, I noticed that for the Google integration, the platform sends "sendUpdates": "none" with every API request, which suppresses the automatic notification email. Likewise, as of a recent commit, Cal sends SCHEDULE-AGENT=CLIENT to the calendar provider to tell it not to send its own notifications.

It seems to me that the same logic should apply to Zoho.

Evidence

This was reported by one of my clients and reproduced through much trial and error on Cal.com.

[Sagarsingh9528]

Hi! I'd like to work on this issue.

I've investigated the behavior and it appears that Zoho Calendar notifications are not being suppressed, unlike the Google Calendar integration which uses sendUpdates: "none" and related notification controls.

I'd be happy to work on a fix and submit a PR. Could this issue be assigned to me?

[GAURAV07C]

Thanks for reporting this! I looked into the codebase and can confirm the issue exists in Cal.diy as well.

Root cause: The Google Calendar integration already suppresses provider-side notifications by passing sendUpdates: "none" on every API call (insert, update, delete). The Zoho Calendar integration doesn't do anything equivalent — so Zoho sends its own invite emails on top of Cal's confirmation emails.

Fix: The Zoho Calendar REST API supports a sendnotification query parameter (0 = suppress all). Adding sendnotification=0 to the create, update, and delete event API calls in packages/app-store/zohocalendar/lib/CalendarService.ts should resolve this.

It's a ~5 line change across 3 methods. Happy to open a PR for this.

[RussianCow]

Where are you guys seeing this sendnotification query parameter? I'm seeing notify_attendee as the parameter across their endpoints—here's an example from their docs.

[Sagarsingh9528]

Good catch, thanks for pointing that out.

I based the implementation on the suggestion in the issue discussion and didn't independently verify the parameter against the official Zoho Calendar API documentation.

I'll review the docs and update the PR to use the documented attendee notification parameter if notify_attendee is the correct option.

[Sagarsingh9528]

Good catch @RussianCow , thanks for pointing that out.

I checked the official Zoho Calendar API documentation and confirmed that notify_attendee is the documented parameter. I've updated the implementation to use notify_attendee=0 instead of sendnotification=0 and pushed a follow-up commit.