Every email provider sets its own rules to determine how it identifies an email as spam. Unfortunately sometime these rules incorrectly mark bookitlive emails as spam.
Unmarking email as spam
Most email providers allow you to unmark email as spam and set up filters so future email are not marked as spam. As each email provider has different process to unmark email as spam you will need to find out how to do this for the email you use. the general process is to find the email in your spam or junk folder, open the email and mark the email as not spam or junk.
Here are some links to the process to unmark emails as spam:
Gmail Unmark email as spam Gmail
Outlook (Search for Outlook safe sender list) Outlook safe sender list
Outlook 365 Unmark email as spam Outlook 365
Corporations and Government agencies
Corporations and Government agencies have their own mail servers that they control and set their own spam policies. A common approach by a Corporation or Government agencies is to mark emails as spam from unknown sources. A whitelist is then used to control the email that they want to accept by adding the details of the sender to their whitelist
The IT dept of the Corporation or Government agencies will need to add the following to their whitelist to stop the email notifications from bookitlive from being marked as spam.