When Invitations Do Not Arrive
Start with the sending domain. It accounts for nearly all of this, and it fails silently.
There is one dominant cause, and a useful test for it.
The test: did you get your briefing while they got nothing? Those two messages are sent in different ways, so that exact pattern points squarely at the sending domain. Your briefing goes through Zyntro's own sending and nearly always arrives; their invitation goes from your domain and is skipped if that is not verified.
If neither of you received anything, the cause is different and usually more mundane — covered below.
Known Issues
I got my briefing but the person who booked got no invitation
No verified sending domain for the organisation. Zyntro will not send a message appearing to come from your domain until that domain is verified, so it skips the invitation rather than sending something that would be rejected or distrusted.
Set up and verify a sending domain in your organisation's email settings, then test with a real booking to an outside address.
Until it is done, every person booking you is receiving nothing: no invitation, no calendar attachment, and no reschedule or cancel links. It is worth treating as urgent if you are taking public bookings.
Neither of us received anything
Usually the booking did not complete, rather than the email failing. A booking is created by the form submission, so a form that did not submit creates nothing to notify about.
Check whether the meeting is actually on the calendar. If it is not, this is a booking problem rather than a notification one — the most common cause being a booking schedule with no connected form.
The invitation arrived but looks like it came from a stranger
The event title is doing the work here, and it is a different field from the title on your booking page.
Set the booking schedule's event title to something a stranger will recognise in their calendar a week later — your business name and the kind of meeting. The customer-facing title on the booking page is written to sell the meeting; the event title is written to be recognised.
The meeting did not appear in their calendar, only in the email
They did not add the calendar attachment, or their mail client did not offer it.
Most mail clients offer to add it automatically; some need a tap. For a customer who is not getting it, the reschedule link in the invitation is a reliable fallback — it shows the booking and its time.
If the attachment is missing entirely rather than merely unused, that points back at the sending domain, since the invitation and its attachment travel together.
I moved the meeting but the attendee's calendar still shows the old time
Either the change notice was not sent, which again points at the sending domain, or their calendar has not processed the update yet.
Confirm the sending domain is verified. If it is, ask whether they received an Event Updated message — if they did and their calendar did not move, it is their calendar software, and the message itself states the new time.
I cancelled a meeting that I had already rescheduled, and the attendee says it is still in their calendar
Calendar software ignores an update it considers older than what it already holds. Zyntro handles this so the later message always wins, so a cancellation after a reschedule should take effect.
Check that the cancellation notice was actually sent — if the sending domain is not verified, it never left. Where it did send and the entry persists, ask them to delete it manually; the notice itself is unambiguous.
A colleague added to the meeting was not notified
Notifications go to the people recorded on the meeting. Someone mentioned in a description but not added as an attendee is not on it.
Add them to the meeting properly rather than referring to them in the text. Only people on the meeting are notified, and on a group calendar only people on the meeting have their time protected.
Invitations are arriving but landing in spam
A sending domain that is verified but not well established, or content that trips filters.
This is ordinary email deliverability rather than anything specific to calendars. A properly verified domain is the foundation; beyond that, consistency of sending over time is what builds reputation.
I want to stop a particular attendee being emailed
For an event you create yourself, each guest has a setting controlling whether they are emailed at all.
Turn off the email invitation for that guest on the event. For a booking made through a booking page, the person who booked is always notified — that is the point of the invitation, and it carries their only means of changing the meeting.
A guest told me they accepted, but the meeting still shows no answer
Either their reply never reached Zyntro, or they answered in a way that is not a calendar response.
Check how they answered. Pressing Yes in a calendar or email invitation sends a reply that Zyntro records. An email saying yes, see you then is a message, not a calendar response, and does not change their state.
If they did use the buttons, confirm your sending domain is verified. The reply address in every invitation lives on that domain, so without it there is nowhere for an answer to arrive.
Some mail software does not send calendar replies at all. If that is the case, their answer will stay at Awaiting reply no matter what they press.
Troubleshooting Guide
Did you receive your briefing?
Is a verified sending domain set up for the organisation?
Did the test invitation arrive?
Frequently Asked Questions
Because an invitation to a meeting with you should come from you. One sent from a generic address is likelier to be ignored and likelier to be filtered, and it would misrepresent who the meeting is with.
Yes. The verified sending domain is what lets Zyntro send as your business generally, so it is worth setting up regardless of calendars.
No. Those bookings exist but their invitations were never sent. If any are still upcoming, the practical fix is to contact those people directly, and consider rescheduling so they receive a proper invitation.
Not in the booking screens, which is what makes testing the only reliable check. Make a real test booking to an outside address whenever your sending setup changes.
No. The sending domain is set once for the organisation and covers every calendar, schedule and form.
No. An update repeats what each guest has already said, so changing a title or a description leaves their answers alone. Moving the meeting to a new time is different — that asks everyone to confirm the new time, which is the correct behaviour rather than a fault.
