Log viewer

How does the log viewer work, AVAST found a virus today on email of course but nothing in the log viewer? How do I get it to work?

What you are looking for is called “Report file” in avast! - the Log is for something else (errors, etc.)
For on-demand scan, you can turn on the creation of the report file in the program settings. For the e-mail scanner, the recent log is stored somewhere in the avast folder, if I remember correctly (data/report?).

\data\report\Resident Protection.txt