which one of these is more common and proper to use when sending a business email
which one of these is more common and proper to use when sending a business email with attachment of some files.

Please find the attached file you requested

Please find the files you requested in the attachment.

Attached you may find the files you requested.

You can find the files you requested at the attachment.

Thanks a lot!

Question

which one of these is more common and proper to use when sending a business email
which one of these is more common and proper to use when sending a business email with attachment of some files.

Please find the attached file you requested

Please find the files you requested in the attachment.

Attached you may find the files you requested.

You can find the files you requested at the attachment.

Thanks a lot!

Answer

I would go with the first sentence, but move "the" before "file".

Please find attached the file(s) you requested.

Answer

I don't think that emails have been around long enough for a standard form to develop.
I think I would use "Please find attached the files you requested".
Your 2nd one is fine. The others are slightly more awkward. The first is the one I would least prefer.