function getAttachment() {
var ss = SpreadsheetApp.getActiveSpreadsheet()
var sheet = ss.getSheetByName('All Data');
var lrow = sheet.getLastRow()
var emails = GmailApp.search('Message Subject',0,1)
for(i = 0;i<emails.length;i++){
var messages=emails[i].getMessages()
for(m=0;m<messages.length;m++){
var attachment=messages[m].getAttachments()[0]
var csv = Utilities.parseCsv(attachment.getDataAsString())
csv.shift()
Logger.log(csv)
if(csv.length<800){
sheet.getRange(lrow+1,1,csv.length,csv[0].length).setValues(csv)
}
}
}
}
The code only searches for the first email with the subject. I intentionally left the emails variable in case I ever want to search for more than 1 message.