I have a text file which I have uploaded here. I want to find all email addresses in this text file. I just know that some of them are after "Subscription Date" expression (I don't know if there is a better way to find all of email addresses in a txt file). I saw several questions like this but they don't work for me. Also I tried this

res = Import["data.txt", "Lines"];
tar = Position[res, "\"Subscription Date\""][[1, 1]];

but this is not the answer. Any ideas?