Mailed them . how can i find out if they were received?

After 4 weeks, you can start checking here:

https://www.irs.gov/refunds

When you mail a tax return, it is a good idea to use a mailing service that will track it like UPS or certified mail.  Then you will know the IRS received it. When you mail your tax return, wait about 4 weeks and then check the IRS site:  

https://www.irs.gov/refunds