I typed in the wrong email address and postmast sent it back. How can I re-send it. HELP, Thank you, Illinois swimmer

If there is someone who can help me I would so appreciate it.  I typed a very important email today however I got ONE letter mispelled in the address and the postmaster marked it a failed in notification to me.  How can I re send it?  I am not computer literate, and I do not care, but this email must get out.  Thank you to who ever responds.  Kind regards,  The Illinois Girl Swimmer