Why Are Booking Notifications and Scheduled Guest Messages Delayed, Pending, or Not Sent?

If a booking arrives (for example you see it in the channel/Pulse) but the booking email notification is late, or the automated/scheduled guest message stays pending or never leaves, one of the situations below is usually the cause.

1. Temporary system-wide delay

Occasionally there is a temporary delay affecting all notifications and scheduled messages across accounts. During these periods:

• The booking still exists and is safe — only the email notification and the scheduled message are delayed.
• Normal delivery is usually just a few minutes; during a delay it can take significantly longer.
• Our technical team is alerted and works to restore normal delivery, after which pending messages and notifications go out.

What to do: If a guest message is time-sensitive (e.g. check-in instructions) and you cannot wait, you can send it manually from the Inbox. Note that once you send a message manually, you may want to cancel the matching scheduled message so the guest does not receive it twice — use the cancel message option in Scheduled messages.

2. Message shows "pending"

A scheduled message in pending status has been created but not yet delivered. During a delay it will normally send once the system recovers. If it has moved to a failed state, it will not be retried automatically — send it manually.

3. Message failed – Booking.com "security filters"

If a scheduled message contains external links, Booking.com may reject it with the error "Message content failed to pass security filters." Booking.com does not allow messages to guests that contain links to external websites. Accepted link types are generally Google Drive or PDF links. Remove or replace the disallowed links and resend manually. See "Why do messages fail to send?" for more detail.

4. Channel hasn't confirmed the booking yet

An automated confirmation can be delayed if the channel has not yet confirmed the reservation — for example when the channel is still verifying the guest's details. The message sends once the channel confirms the booking.

5. Booking appears cancelled after a channel/account change

After a channel re-sync or a move between main accounts, a reservation can appear cancelled even though it is valid (e.g. it changed channel while remaining in the main account). Because the integration reads this as a cancellation, the scheduled welcome message may not be sent. Report the affected reservation to support so it can be corrected; once updated, check upcoming reservations to confirm they display correctly.

6. Message sent immediately instead of before check-in

If a "before guest arrival" rule (e.g. 7 days before check-in) is created after a booking is already received, and the off-schedule option is enabled, the message is sent at booking creation time instead of the scheduled date. This is expected behavior for rules with the option "For bookings made less than [timing] in advance, send the message at booking creation time" enabled. Also check whether the initial message the guest received actually came from the channel itself rather than from your rule.

7. Manually added reservations don't send emails

If you add reservations manually and notifications don't go out, it may coincide with a temporary system delay. In that case, do not re-enter the reservations — re-entering makes it harder to trace what happened. Wait for the delay to clear or contact support with the booking references.

When to contact support

Provide the affected booking reference(s) so support can check the notification and message logs. If a message has already failed, send it manually, since failed messages are not retried automatically.

Updated on: 05/10/2026