How to find the number of occurrences of a string in file using windows command line?

Question

I have a huge files with e-mail addresses and I would like to count how many of them are in this file. How can I do that using Windows\' command line ?

I have tried

Answer 1

I found this on the net. See if it works:

findstr /R /N "^.*certainString.*$" file.txt | find /c "@"