How can I check to see if they recieved my mail in tax papers?

If you did not use some type of tracking service when you mailed the tax return, you will not know when or if the IRS received the federal tax return.

If you have a tax refund on the federal tax return use the federal tax refund website to check the refund status - https://www.irs.gov/refunds

The IRS is not processing paper tax returns at this time.

Go to this IRS website for information - https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue

The IRS is not currently able to process individual paper tax returns. If you already have filed via paper but it has not yet been processed, do not file a second tax return or write to the IRS to inquire about the status of your return or your Economic Impact Payment. Paper returns will be processed   once processing centers are able to reopen.