I've created a spreadsheet with various checkboxes throughout it to replace
an older version. Unfortunately the old version is protected and I don't
know the password so I had to start from scratch. Both versions have
checkboxes but only the new one gives a Security Warning stating "Macros may
contain viruses. It is usually safe to disable macros, but if the macros are
legitimate, you might lose some functionality."
The spreadsheet is going to be distributed to clients so I can't just change
my security settingsget rid of the message. If I leave it there and someone
doesn't allow the macro they can't use the checkbox.

How do I get the spreadsheet to not give a Security Warning but still keep
the checkboxes active?