If an address rejects a message you sent from a booking, event, or contact, you get an in-app alert and an email. The person who sent it — and, on a booking, the sender on your side of the booking — sees it. The rest of the Account is not notified.
There are two kinds of bounce. A hard bounce means their inbox rejected the address, so they did not get it. A temporary bounce can be an out-of-office, an auto-reply, or a brief delivery hiccup — they may still have received the message.
What to do after a hard bounce
The alert title is Email didn't go through (or Challenge email didn't go through for a hold challenge).
Open the alert, or use View booking, View event, or View contact.
Check the recipient address on that record.
Fix the address if it is wrong, then send again.
If it was a challenge on a hold, the date is still on hold. Correct the address and send the challenge again.
What to do after a temporary bounce
The alert title is Email got a temporary bounce (or Challenge email got a temporary bounce).
Wait to hear from them before treating this as a failed send. Do not assume they missed the message. If it was a challenge, the date is still on hold.
Common questions
Who gets the alert? The person who sent the email, and on a booking the sender on your side — if they are on the Account. Scheduled or system sends with no sender may not notify anyone.
Does this cancel a hold? No. A bounced challenge does not release the date.
Will I get another alert if the same email bounces again? Once the send is already marked bounced, a repeat bounce on that same send does not notify you again.