@someone
A tax agency doesn't always acknowledge receipt, since they get many bags and carts of mail each day. I've had the IRS not acknowledge my receipts before, or send them days later. During the Coronavirus situation, processing at tax agencies has been thrown into a mess.
If necessary, you can phone them at some point and ask if they have received it or what they want you to do. If it were me, I personally wouldn't send a second return unless the tax agency told me to.
You can also speak to your post office to have them check on it for you.
Does it show up when you use the info in this FAQ? (it might not, if they haven't been processing manual returns lately)
https://ttlc.intuit.com/community/refund-status/help/how-do-i-track-my-california-tax-refund/00/2656...
