The only way to file your 2018 return is to print, sign and mail it. However, you do not seem to know why it was rejected--or at least you have not said why. If it was for incorrect AGI--the most common reason -- then it no longer matters since you only needed the AGI to e-file. If something was wrong and needs to be changed/corrected on the return, you will need to used desktop software to correct the return before you print and mail it.
The email telling you that the return was rejected also has the rejection code or message -- what does it say?
(And you did get an email when it was rejected--did you check your spam folder?)
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.
**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.**
