If Mac says it “can’t verify” FINDmsg

This is normal. Apple blocks apps not sold in the App Store until you allow them once.

1. Click the link below to open Privacy & Security settings.
2. Scroll to the bottom.
3. Click Open Anyway next to FINDmsg / Install FINDmsg.
4. Enter your Mac password if asked.
5. Open Install FINDmsg again.

Open Privacy & Security settings

Then go back and double-click Install FINDmsg.