It just has to be postmarked by the deadline. It is always a good idea to use a service that will provide you with a receipt or tracking so you know the IRS received your return.
To send your tax return by mail and get a receipt to see that the IRS received it:
https://www.usps.com/taxes/welcome.htm
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
