Ejectify

Ejectify automatically unmounts external disks when your Mac starts sleeping and mounts them again after it wakes up.
Requires macOS 10.12 or later.
FEATURES
☆ Prevents annoying Disk not ejected properly notifications when your Mac wakes up.
☆ Prevents connected external disks and their volumes to get corrupted.
☆ Configure what volumes should be (un)mounted automatically, optionally forcefully.
☆ Available in English, Dutch, German, French, Spanish, Russian, Japanese, Portuguese, Hindi and Arabic.
☆ Configure when volumes should be unmounted automatically:
• When screensaver started.
• When screen is locked.
• When screens started sleeping.
• When system starts sleeping.
☆ Automatically mounts volumes again when your Mac or screens wake up, optionally after a delay.
☆ Unmount all volumes instantly with the click of a button.