Mail Shield ~ Avast free anti-virus for Mac

Can anyone tell what to do, if anything, about a couple of threats showing in Mail Shields ‘History’. Right clicking on them doesn’t give any removal options. There have also been a couple of orange alert boxes on the desktop warning about these emails. There is no sign of emails in any account in Mail including Trash folder. Any help gratefully accepted
Thanks
Alan

Hello,
if the mail shield notified you about infections, it has also blocked a download of them from a mail server to your computer. There is no particular action you need to do. If you were notified repeatedly about the same infections, then the infected attachment would be still present at your mail server and you would need to delete corresponding emails.

Mail Shield history is only a log of past findings with a basic information about them.