Mistake In an Email to Professor that is already sent out I wrote an cold email to a professor to inquire about research opportunity. But I made an unforgivable mistake that I wrote his institution name wrong in the text. I should have wrote 'your research group in [institution A]',  but I somehow subconsciously wrote [institution B]. This is going to make him feel that I am cold emailing a couple of professors which is indeed what I am doing(but I am not writing generic emails), and this error escaped my three time re-examination. 
How should I compose my follow-up email to correct this or is there anything else I can do?? Thanks guys. Cold emailing professor is already making me feel weird.
The way I see it, you have two choices:

Do nothing - I do not endorse this, as it transmits the message that you do not care, or even worse, you did it on purpose;

Send another e-mail with the proper apologies (do not over-do it), and correct the mistake.


The message can be as simple as:

Dear ....
In previous e-mail I wrote: &quot;...ABC...&quot; while I intended to write &quot;...XYZ...&quot;. Please accept my apologies, this was totally unintended. I cannot even explain it to myself.
Yours...

Words may vary.