I probably didn’t explain myself well.

On Gmail [email protected] is an “alias” for [email protected]. So if you give someone [email protected] hoping that will help you map random string to that particular sender, you’re fucked - because anyone who sees [email protected] knows it’s an alias for [email protected], they can just email that directly and bypass your cleverness.

If you’re using a sane alias provider like you described, then it’s likely not an issue.