I am a secretary and would like to know if I need to write «Please find attached herewith» when sending an attachement by e-mail or if «Please find attached» is sufficient. Using both seems redundant to me.
Welcome to Using English!
It will depend to some extent on your culture. Your first suggestion is very formal. It would be almost laughably formal in my company.
There is a reason you are sending these documents. Just say what it is.
The spreadsheet you requested is attached.
I've attached the Anderson report. Please review and let me know about any changes that are required.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.