The IRS - not eFile.com - has rejected your return and you are required to make a correction. Apparently the SSN on the return belongs to a deceased person regarding to the IRS.
Solution: Please sign in to your eFile.com account now and click on My Return in the upper left and review the IRS message on the right.
1. Sign in: https://mytaxes.efile.com/1040/SignIn/
2. Click on Name & Address and the left and verify the SSN on the right side. If this individual indeed is deceased please indicate so via the link: I'm filing for a deceased taxpayer
If all SSNs are correct as they are now on your return, then you need to print and mail your return. Please go to your My Account and download, print, sign and mail in your returns. Otherwise make correction and re-eFile at no charge.
Here are the mailing addresses: https://www.efile.com/irs-mailing-addresses/
If you have questions, please contact us as soon as possible so we can assist you with your Tax Return.