I downloaded the 2018 deluxe turbotax and it want let me e-file or send it to my work email so I can print and send it by mail.

You can no longer efile a 2018 tax return. Efile is available for the current tax year, 2019, only. The IRS requires that prior year returns be printed and mailed. You should be able to download a PDF of your tax return. This document can be emailed to another computer if necessary.

E-filing for a 2018 return closed permanently in mid-October of 2019.  The only way to file the 2018 return is by mail.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Remember that federal and state returns must be mailed separately to separate addresses.