R - 计数行数@符号

I have a list of records with IDs (some of which are usernames and some of which are email addresses). I'd like to know how many are email addresses. I was thinking an easy way to do this would be count how many of the rows contain the @ symbol but I can't get a function to work to do this. Any help is appreciated! I have a list of records with IDs (some of whic