my notice to the owner was returned because the address wasn't correct. do i need to resend the notice?
That is a good question and it depends on the type of notice. I assume since you are talking about the owner that you mean a notice of furnishing. In Ohio a notice of furnishing only needs to be served on an owner who has recorded a notice of commencement in the county where the project is located. If a notice of commencement was recorded, the notice will list an address for the owner (or the owner's representative). Notices of furnishing sent by subcontractors should be sent to the address on the notice of commencement.
If your notice was sent to this address, it is deemed to be served, even if it was returned to sender, so long as it was served by certified mail or something similar with tracking information.
If this is a different notice, the question may be answered by your contract.