Attachment virus warnings

I’ve recently uninstalled AVG and installed Avast. With AVG, any e-mails containing an attachment were previewed and before you opened the attachment the screen told you if,or not they were virus free. I can’t see a similar function on Avast. There doesn’t seem to be any warning or information about the attachments. How can I ensure that attachments are virus free before I open them?
Thanks all…Andy

If they are not you would get warning while downloading email from mail server.
Mail Heuristics will also give you warnings on new or potentially dangerous attachements.