Antispam - Main settings

You can adjust the antispam sensitivity and other options.

Sensitivity - Indicate how strictly antispam analyzes incoming emails to identify potential spam. With higher sensitivity, the filter is more likely to catch spam, but also more likely to mark legitimate messages as spam.
Mark in subject of spam/phishing messages - Emails Avast recognizes as spam or phishing are visibly marked in the subject field so that you can identify them quickly. The text can be customized.
Add recipients of outbound emails to whitelist automatically - When selected Avast automatically whitelists recipients of emails you send so replies are not treated as spam. This option is disabled by default.
Retrieve new rules - Keep antispam filters updated with new rules for identifying spam. By default, antispam checks for new rules every 300 seconds (5 minutes).
Enable LiveFeed - Antispam checks all incoming emails against an online database of global spam messages before carrying out the heuristic and other checks. The amount of data transferred is very small, so it is recommended to enable this service.

You can enable the Avast add-in in MS Outlook: Options ▸ Add-ins ▸ Avast Addin.

With MS Outlook installed, you can also:

Move messages identified as spam to a separate junk folder automatically, so that they do not appear in your inbox.
Add addresses of all contacts in your Microsoft Outlook address book to the antispam's whitelist so that they are never treated as spam.
Send samples of emails incorrectly marked messages for further analysis. Choose Yes to send automatically, No to ignore automatically, or Ask if you want to choose on each occasion.