I printed this, placed it and an LED tea light within, and put the assembly on the mailbox post. Probably against all regulations from the post office and the HOA. No complaints so far.

There was a 5% defect on the top of the arms when printed in vase mode. In standard mode, it printed easily.

The basic approach was provided by Vladimir Murano on Desktop Makes, who has a great inventory of instructions for Fusion 360.