Can I still submit online my mail tax return that was rejected

not following the question.

if your tax return was rejected upon efiling, you have two options

1) fix whatever the issue was and re-submit

2) print, sign and mail it 

What do you mean by "my mail tax return that was rejected"?   Mailed tax returns are not rejected.   If you mailed your tax return to the IRS in an envelope, then a human opened it and and entered it into the system for processing.   An e-filed return can be rejected, for various reasons.   Sometimes the problem is "fixable" and you can fix it and try to e-file again.

If your e-file was rejected, you can try to fix the problem and e-file it again, or you can choose to just print it, sign and date it in ink, and mail it in an envelope.